media: verisilicon: AV1: Fix tx mode bit setting

media: verisilicon: AV1: Fix tx mode bit setting

AV1 specification describes 3 possibles tx modes: 4x4 only, largest and
select. The hardware allows 5 possibles tx modes: 4x4 only, 8x8, 16x16,
32x32 and select. Since the both aren't exactly matching we need to add
a mapping function to set the correct mode on hardware.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Fixes: 727a400686a2c ("media: verisilicon: Add Rockchip AV1 decoder")
Cc: stable@vger.kernel.org
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>