Replace all calls to s_mbus_fmt in bridge drivers by calls to the
set_fmt pad op.

Remove the old try/s_mbus_fmt video ops since they are now no longer used.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Prabhakar Lad <prabhakar.csengg@gmail.com>
Acked-by: Scott Jiang <scott.jiang.linux@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>