msm_vidc: venc: update input buffer count for firmware

Setting max buffer count to firmware and later querying the buffer
requirements after setting resolution and other properties will result
in firmware returning max buffer count. To avoid allocating extra
buffers, this change sets firmware with the max buffer count
requested by client and firmware.

Change-Id: I3d5e800ea3cdea4064d4e9d8453eb4d925c77f8c
Signed-off-by: Ashray Kulkarni <ashrayk@codeaurora.org>