hwc/copybit: Add Color layer support in MDP Copybit composition.

1. Color layer has a destination rectangle, RGBA color and plane
   alpha. There is no gralloc buffer. Layer flag HWC_COLOR_FILL
   denotes color layer. MDP BLIT happens via MDP_SOLID_FILL mode.
2. There is no color member in HWC layer, so RGBA color value is
   passed via "tranform" member from framework to HAL.
3. Update HWC query to enable framework to query for Color layer
   support in HAL, at run-time.

Change-Id: I2c698007c1689779fe86d549093bb5285432dc5f

hwc/overlay: Add Color layer support in MDP Composition.

1. Color layer has a destination rectangle, RGBA color and plane
   alpha. There is no gralloc buffer. Layer flag "HWC_COLOR_FILL"
   denotes a Color layer.
2. There is no color member in HWC layer, so RGBA color value
   is passed via the "tranform" member from framework to HAL.

Change-Id: I8769fd3f5febcaf952a1456de0a4262679c9a0e4
Use msm8974 directory for msm8226

- The code in msm8x26 directory is oudated and 8974 works
  with no issues.
- Remove unneeded msm8x26 directory
- Add symlink from msm8226 to msm8974 so current macros that
  use display/$(TARGET_BOARD_PLATFORM) to find needed headers
  continue to work as expected.
Change-Id: I5fe4a86674c9f278a951a6ad7a89af6f93c491cb
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_hardware_qcom_display into HEAD