Unbreak libgui

Change I2c0f05d1f70b96ad801971f23f6f9cf4e0fa7167 broke libgui for a
bunch of pre-4.1 blobs by changing the surfaceclient API, so bring
it back

Change-Id: I1f6ce3b886539d0e972bbe41116192bf162be968
make TARGET_QCOM_DISPLAY_VARIANT more parametric

Change-Id: I36bba3ba96e174b443d800fd79957a1f428899df
Merge remote-tracking branch 'cm/cm-10.2' into jb3