[media] cx23885: Ensure the MPEG encoder height is configured from the norm

Bugfix: The height was not always correctly configured if switching between
different video standards. Change the encode height based on the standard.

Signed-off-by: Steven Toth <stoth@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>