drm_hwcomposer: add GLES compositor

This patch adds the GLES based compositor. This doesn't actually make
the hwcomposer use it, which will come in a later commit. This
version of the compositor uses syncpoints optimally and has no
fallback for the case where too many (32 currently) layers overlap.

(cherry picked from commit 6996227fe43bcf78c6e692e8098bdddb95bfda6e)

Change-Id: I3503cb5d1b309ae06d1ed2a8d244640ad81eda9e
2 files changed