vpu: encoder: implement propose_allocation
vpu: encoder: implement propose_allocation

This allows upstream elements to use the phys mem buffer pool.

Signed-off-by: Philip Craig <e888d2bd6f13f82caa51a37c03d034c76f661ba3@blackmoth.com.au>
Signed-off-by: Carlos Rafael Giani <d7d2e6b3863b2910d2ca34828bc651c85d88df6f@pseudoterminal.org>

Josuercuevas/gstreamer-imx,commshare/gstreamer-imx,commshare/gstreamer-imx,Josuercuevas/gstreamer-imx