[media] drivers: media: use module_platform_driver_probe()

This patch converts the drivers to use the
module_platform_driver_probe() macro which makes the code smaller and
a bit simpler.

Signed-off-by: Fabio Porcedda <fabio.porcedda@gmail.com>
[g.liakhovetski@gmx.de: also remove redundant .probe initialisation]
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>