media: rkisp1: Make rkisp1_isp_mbus_info common

The upcoming CSI receiver split from the ISP to a separate source file
will need to be able to access the list of formats supported by the
driver. Move it out of the ISP's header and into the common header, and
add helper functions for accessing it so that the format list doesn't
need to be stored in the header.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Dafna Hirschfeld <dafna@fastmail.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>