liboverlay: Add support for MDSS Bandwidth Compression

- This adds support for Bandwidth Compression.
- If MDSS supports BWC, then we set BWC flags
  to both Rotator(encode) and overlay(decode)

Change-Id: I6f7800716a2ce2ab855f4c0b1a53cd96f7d06d74
diff --git a/liboverlay/overlayRotator.h b/liboverlay/overlayRotator.h
index c02dfba..120721c 100644
--- a/liboverlay/overlayRotator.h
+++ b/liboverlay/overlayRotator.h
@@ -198,6 +198,8 @@
     /* Calculates the rotator's o/p buffer size post the transform calcs and
      * knowing the o/p format depending on whether fastYuv is enabled or not */
     uint32_t calcOutputBufSize();
+    // Calculate the compressed o/p buffer size for BWC
+    uint32_t calcCompressedBufSize();
 
     /* MdssRot info structure */
     mdp_overlay   mRotInfo;