hwc: Remove need for intermediate buffer for c2d composition

A-Family device NON PRO 8960 uses copybit composition. The
intermediate buffers allocated are not needed when we can
compose onto fb frame.

Conflicts:
        libhwcomposer/hwc_copybit.cpp
        libhwcomposer/hwc_utils.cpp

Change-Id: Icc68641c5b35e3a2e99654264daa058c95f48c43