media: venus : Addition of control support - V4L2_CID_MIN_BUFFERS_FOR_OUTPUT

V4l2 encoder compliance expecting minimum buffers support for
the application to allocate buffers as per the control support values.

Signed-off-by: Viswanath Boma <quic_vboma@quicinc.com>
Signed-off-by: Vikash Garodia <quic_vgarodia@quicinc.com>
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>