V4L/DVB: Saa7134: select FW_LOADER

The saa7134 drivers uses request_firmware()
and thus needs to select FW_LOADER.

Signed-off-by: maximilian attems <maks@sternwelten.at>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>