display: Allow build for all QCOM platforms

Change-Id: I82b62206ad3d827e1af68041f88f86f18dc19b90
display: Use fences for all targets

Change-Id: I89a8b661dba7919707ba26ff35fb294b22aaba67
hwc: Don't allow downscale with alpha on MDP <= 4.1

Change-Id: I86a9031a4c5ff28e9bb10f6ed7405946b1c600cc
Merge branch 'cm-10.1' of https://github.com/CyanogenMod/android_hardware_qcom_display into HEAD
Revert "libexternal: Call new IOCTL to commit on external display"

This reverts commit 3825f25827d3e23b0bc12e5bf453c851d4c238d8.