Conditionally revert "Revert "sf: Make sure HWC_BLENDING_NONE is set for opaque layer""

 * This behavior is REQUIRED on newer Qualcomm hardware, or undefined
   behavior such as artifacts or garbage will appear. Scope this revert
   to QCOM_BSP_LEGACY only!

This reverts commit 18161438.

Change-Id: I1f5bb57d1fa8750e854f01884bb675e4b9f2bed5