hwc: Don't permit rotator use under certain conditions

These include constrained targets, with external connected which could
lead to a scarcity of pipes. Furthermore owing to a scarcity of writeback
interfaces, even if pipes are available, we may not be able to still
use rotator.

Change-Id: Ie2fb4c1726f32addcace89c268a126abe0cddbe0
diff --git a/libqdutils/mdp_version.h b/libqdutils/mdp_version.h
index c34c0a4..f7b16fa 100644
--- a/libqdutils/mdp_version.h
+++ b/libqdutils/mdp_version.h
@@ -53,6 +53,12 @@
     MDSS_V5     = 500,
 };
 
+enum mdp_rev {
+    MDSS_MDP_HW_REV_100 = 0x10000000,
+    MDSS_MDP_HW_REV_101 = 0x10010000, //8x26
+    MDSS_MDP_HW_REV_102 = 0x10020000,
+};
+
 enum {
     MAX_DISPLAY_DIM = 2048,
 };
@@ -84,6 +90,7 @@
     bool supportsDecimation();
     uint32_t getMaxMDPDownscale();
     bool supportsBWC();
+    bool is8x26();
 private:
     int mMDPVersion;
     char mPanelType;