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