media: ti-vpe: cal: Name all cal_dev pointers consistently

Name all variables pointing to a cal_dev instance 'cal', instead of a
combination of 'caldev' and 'dev'. 'caldev' is only used in a few places
and could have been renamed to 'dev', but 'dev' is confusing as it's
also used for struct device instances. This generates lots of changes,
but increases readability.
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>