media: ti-vpe: cal: Drop V4L2_CAP_READWRITE

The V4L2 read/write API is inefficient and makes little sense for
devices that handle frame-based formats. Applications shouldn't use it,
drop its support from the driver.

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>