media: ti-vpe: cal: Drop cal_ctx m_fmt field

The struct cal_ctx m_fmt field stores the media bus format for the
context input. Only the format 'field' field is used, store it in the
video format instead, and drop m_fmt.

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>