media: ti-vpe: cal: Move DT parsing to CAMERARX

The DT port nodes corresponding to the CSI-2 inputs belong to the
CAMERARX instances. Move parsing of the DT properties to a new
cal_camerarx_parse_dt() function, called by cal_camerarx_create().

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.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>