commands/*: Replace license and copyright boilerplate by SPDX identfiers ...

While at it also drop references to the non-existing CREDITS file and do
some small rearrangements for some uniform formatting.
(SPDX-License-Identifier first, then copyright texts and then an empty
line.)

The advantage is that these specifiers are machine-parseable which helps
license conformance.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

commands: unify newlines for options ...

The BAREBOX_CMD_HELP_OPT macro adds a newline to the string, but users
of the macro inconsistently add another newline resulting in empty
newlines for some commands, but not for others. Remove any newline in
the description and rely on BAREBOX_CMD_HELP_OPT for the formatting.

Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

commands: firmwareload: add CMD_GROUP ...

To be able to build the documentation the CMD_GROUP macro needs
to be defined. Without this the firmwareload command breaks "make docs".

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

Add a Firmware programming framework ...

This framework handles a list of registered Firmware programming handlers
to unify a firmware programming interface by hiding the details how
to program a specific Firmware in its handler. This is created with FPGAs
in mind but should be usable for other devices aswell.
A user has two possibilities to load a firmware. A device file is create
under /dev/ which can be used to copy a firmware to. Additionally a
firmwareload command is introduced which can list the registered firmware
handlers and also to upload a firmware.

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>