media: ti-vpe: cal: Inline cal_get_camerarx_regmap() in caller

The cal_get_camerarx_regmap() function is called in a single place.
Inline it in its caller, as it results in a clear code flow.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Benoit Parrot <bparrot@ti.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>