sunxi: video: Add sun6i support

Besided needing the usual sun6i specific ahb1_reset bits poking, it turns out
that sun6i also needs the drc to be taken out of reset and clocked even though
it is in pass-through mode.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Anatolij Gustschin <agust@denx.de>