[ALSA] do not depend on FW_LOADER when internal firmware images are used

Since request_firmware() is no longer used when the internal firmware
images are used, it is no longer necessary to depend on FW_LOADER in
this case.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>