media: ti-vpe: cal: Store instance ID and cal pointer in cal_camerarx

Store a pointer to the cal_dev and the cal_camerarx instance number in
the cal_camerarx structure. This prepares for passing a cal_camerarx
pointer instead of a cal_ctx pointer to multiple functions that deal
with the CAMERARX.

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>