[media] drx-j: get rid of function prototypes at drx_dap_fasi.c

Reorder functions and data at drx_dap_fasi.c, in order to avoid
having function prototypes.

This is in preparation to merge this code inside drxj, removing
some duplicated bits there, and getting rid of yet another
abstraction layer.

Acked-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>