rename file_operations -> cdev_operations ...

Linux also has struct file_operations which are something different.
Rename our file_operations to cdev_operations which better matches
what we have.

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

string: Fix (v)asprintf prototypes ...

Our asprintf and vasprintf have different prototypes than the glibc
functions. This causes trouble when we want to share barebox code
with userspace code. Change the prototypes for (v)asprintf to match
the glibc prototypes. Since the current (v)asprintf are convenient
to use change the existing functions to b(v)asprintf.

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

common: firmware: include libfile ...

Fixes
common/firmware.c:206:2: error: implicit declaration of function 'copy_file'
in a number of configuration where this file isn't pulled in through
other headers.

Signed-off-by: Lucas Stach <l.stach@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>