[media] staging: as102: Declare local variables as static

As pointed out by sparse:
drivers/staging/media/as102/as102_fw.c:29:6: warning: symbol 'as102_st_fw1' was not declared. Should it be static?
drivers/staging/media/as102/as102_fw.c:30:6: warning: symbol 'as102_st_fw2' was not declared. Should it be static?
drivers/staging/media/as102/as102_fw.c:31:6: warning: symbol 'as102_dt_fw1' was not declared. Should it be static?
drivers/staging/media/as102/as102_fw.c:32:6: warning: symbol 'as102_dt_fw2' was not declared. Should it be static?
drivers/staging/media/as102/as102_usb_drv.c:194:25: warning: symbol 'as102_priv_ops' was not declared. Should it be static?
Also use the const qualifier on the firmware name strings.

Signed-off-by: Mauro Dreissig <mukadr@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>