complete: Add devicetree completion ...

The of_* commands take devicetree nodes as parameters. Add a
devicetree completion function to ease passing nodes to these
commands.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

commands: harmonize in-barebox documentation ...

This patch does probably too much, but it's hard (and very
cumbersome/time consuming) to break it out. What is does is this:

* each command has one short description, e.g. "list MUX configuration"
* made sure the short descriptions start lowercase
* each command has one usage. That string contains just the
  options, e.g. "[-npn]". It's not part of the long help text.
* that is, it doesn't say "[OPTIONS]" anymore, every usable option
  is listed by character in this (short) option string (the long
  description is in the long help text, as before)
* help texts have been reworked, to make them
  - sometimes smaller
  - sometimes describe the options better
  - more often present themselves in a nicer format
* all long help texts are now created with BUSYBOX_CMD_HELP_
  macros, no more 'static const __maybe_unused char cmd_foobar_help[]'
* made sure the long help texts starts uppercase
* because cmdtp->name and cmdtp->opts together provide the new usage,
  all "Usage: foobar" texts have been removed from the long help texts
* BUSYBOX_CMD_HELP_TEXT() provides the trailing newline by itself, this
  is nicer in the source code
* BUSYBOX_CMD_HELP_OPT() provides the trailing newline by itself
* made sure no line gets longer than 77 characters
* delibertely renamed cmdtp->usage, so that we can get compile-time
  errors (e.g. in out-of-tree modules that use register_command()
* the 'help' command can now always emit the usage, even without
  compiled long help texts
* 'help -v' gives a list of commands with their short description, this
  is similar like the old "help" command before my patchset
* 'help -a' gives out help of all commands

Signed-off-by: Holger Schurig <holgerschurig@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

commands: group 'help' output ...

The old output of "help" was just producing a long list, that usually
scrolled of the screen (even on a X11 terminal). This list is more
compact, and also sorted by groups.

The old output format (plus grouping) is now available with 'help -v'.

Example:

   Information commands:
     ?, devinfo, help, iomem, meminfo, version
   Boot commands:
     boot, bootm, go, loadb, loads, loadx, loady, saves, uimage
   ...

Signed-off-by: Holger Schurig <holgerschurig@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

OF: base: rename of_free to of_delete_node ...

of_free is misleading about the actual purpose of the function. There is
already a of_create_node counterpart, so rename of_free to of_create_node
and update all users accordingly.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

OF: base: sync of_find_node_by_path with linux OF API ...

Barebox of_find_node_by_path requires a node to be passed as start node
to start searching. Linux OF API does not pass this node and no current
user of it in barebox is passing anything else than the root node.
Therefore, we rename current function to of_find_node_by_path_from and
introduce a Linux OF API compatible of_find_node_by_path that always
passes the current root_node. Also, all current users of that function
are updated to reflect the API change.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

of: remove unused libfdt ...

Now that we are completely independent of libfdt remove the unused
code.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

of_* commands: print usage when insufficient arguments are given ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

of: Add root node argument to of_find_node_by_path ...

This makes of_find_node_by_path usable with multiple trees.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

of_node command: use of_create_node ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

commands: Add of_node command ...

This command allows to create/delete device nodes.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>