media: venus : Addition of EOS Event support for Encoder

V4l2 encoder compliance expecting End of stream Event registration
support for Encoder.

Signed-off-by: Viswanath Boma <quic_vboma@quicinc.com>
Signed-off-by: Vikash Garodia <vgarodia@qti.qualcomm.com>
Signed-off-by: Dikshita Agarwal <dikshita@codeaurora.org>
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>