display: Add support for dynamic refresh rate

- The primary panels refresh rate can be change by clients
- Required refresh rate will be set by client using metadata
- If there are multiple clients requesting, it will be used only
  when the refresh rates are equal, else it resets to default
- Set the new refresh rate only when there are only YUV layers
  updating or when the list has only one RGB layer updating
- MdpVersion gets the dyn fps capabilities from panelInfo

Change-Id: If3e7e6b2f028eb301399c4d32c748eed8a97c41f
diff --git a/libhwcomposer/hwc.cpp b/libhwcomposer/hwc.cpp
index 6f4f9c6..099a82e 100644
--- a/libhwcomposer/hwc.cpp
+++ b/libhwcomposer/hwc.cpp
@@ -792,6 +792,8 @@
     dumpsys_log(aBuf, "Qualcomm HWC state:\n");
     dumpsys_log(aBuf, "  MDPVersion=%d\n", ctx->mMDP.version);
     dumpsys_log(aBuf, "  DisplayPanel=%c\n", ctx->mMDP.panel);
+    dumpsys_log(aBuf, "  DynRefreshRate=%d\n",
+                ctx->dpyAttr[HWC_DISPLAY_PRIMARY].dynRefreshRate);
     for(int dpy = 0; dpy < HWC_NUM_DISPLAY_TYPES; dpy++) {
         if(ctx->mMDPComp[dpy])
             ctx->mMDPComp[dpy]->dump(aBuf, ctx);