hwc: Add vpu client

Stub implementation of VPU in HWC.
This commit passes through binder calls from HWC
to the VPU library. It also has stub prepare/draw calls
in the VPU client object which can be used to configure
VPU in the composition cycle.

Change-Id: I2606f2884e870448d29ef26e02faac92e157e2c6
diff --git a/libhwcomposer/hwc_utils.h b/libhwcomposer/hwc_utils.h
index d77673b..c5a7be9 100644
--- a/libhwcomposer/hwc_utils.h
+++ b/libhwcomposer/hwc_utils.h
@@ -57,6 +57,7 @@
 class CopyBit;
 class HwcDebug;
 class AssertiveDisplay;
+class VPUClient;
 
 
 struct MDPInfo {
@@ -351,6 +352,7 @@
     qhwc::MDPComp *mMDPComp[HWC_NUM_DISPLAY_TYPES];
     qhwc::HwcDebug *mHwcDebug[HWC_NUM_DISPLAY_TYPES];
     qhwc::AssertiveDisplay *mAD;
+    qhwc::VPUClient *mVPUClient;
 
     // No animation on External display feature
     // Notifies hwcomposer about the device orientation before animation.