msm: vidc: allow larger mbpf limit

mbpf limit is mainly to limit memory consumption, no need to
couple with mbps workload limit.
Modify mbpf limit to larger value for lito to allow more
instances with low fps or non-realtime.

Change-Id: I0b781748aa27532fb1fa99833d252e727452ae26
Signed-off-by: Qiwei Liu <qiweil@codeaurora.org>