Staging: slicoss: use request_firmware

This should make the driver use request_firmware() instead of a static
firmware.
Some obvious things are missing:
1) The unneeded header files are not removed yet. This is to keep the
   patch size small.
2) The .bin files are missing so the driver doesn't have what to load.
3) Testing. None of this was tested. It does compiles OK though :)

Signed-off-by: Lior Dotan <liodot@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>