media: allegro: remove external QP table

The VCU allows to specify the QP per frame and coding unit. A buffer
that specifies the QP is passed via the ep2 field in the ENCODE_FRAME
message.

The driver currently does not support the external QP table. Simplify
the driver by not setting the ep2 fields at all.

Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>