media: imx: imx-media-fim: Replace macro icap_enabled() with function

Replace the macro icap_enabled() with a static function to comply
with Linux coding style standards.

Signed-off-by: Brent Pappas <bpappas@pappasbrent.com>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>