p54: introduce new names for device firmwares

Johannes thought it would have been a good idea to change the firmware names.

Note: we still have fallbacks in case our users don't want to "break their running system",
but we won't advertise them with MODULE_FIRMWARE.

Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>