disp: msm: use vzalloc for large allocations

Large allocations using kzalloc can lead to timeouts. This updates
the allocation calls accordingly to use vzalloc to remove
requirements on contiguous memory.

Change-Id: Ica54483787509ed0e9283289fc9d523e8cde9238
Signed-off-by: Nilaan Gunabalachandran <quic_ngunabal@quicinc.com>
Signed-off-by: Jayaprakash Madisetty <quic_jmadiset@quicinc.com>