SF: Add flag for swaprect status in HAL

We need to check in HAL whether swap rect
is enable or disable to calculate wormhole region.

Change-Id: I4fbff4119856e41694e2065141b40fdd7a15f375
SurfaceFlinger: Change to support framebuffer flip for 2D blitters

- Surfaceflinger does not flip framebuffers when there are
  no layers marked for HWC_FRAMEBUFFER
- This change checks for the HWC_BLIT flag and will request a flip
  to a new FB_TARGET buffer even if there are no FRAMEBUFFER layers

Change-Id: I1cb44389a05c9ec049d7f0d39c288feccb11a91c
Display: Define new composition type for blit composition

This change defines a new flag 'hasBlitComp' to identify
blit composition. This flag is used to enable the swap rect
feature for blit composition cases.

Change-Id: Ic523e19796a893efbfc3bff300d1f982cba5ddfa
surfaceflinger: Conditional compilation for swaprect feature

 * Since this now calls into the HAL, we can only support it on
   devices which use the new version.

Change-Id: I231d70ac3d17fd2198f3929057c1edb0f158c099