hwc: Fallback to GPU if source image width or height is less than 2

There is h/w limitation when MDP_OP_SCALE_RGB_ENHANCED bit and
MDP4_OP_SCALEX_EN or MDP_OP_SCALEY_EN bit is set.
The minimum block size is 2x2. MDP will hang if the source RGB image
height or width is equal to 1. Hence fallback to GPU in such cases.

Change-Id: I7333b097fd26bfb888865de9c39d1664bc87acca
2 files changed