sdm: Add mask layer flag support to input buffer flags.

Set DISABLE_MASK_LAYER_HINT property to disable
this hint.

Change-Id: I526025e2c32d386877b4b0b70c6423642421213f
CRs-Fixed: 2396411
diff --git a/include/display_properties.h b/include/display_properties.h
index 8f5b7df..cd7ef15 100644
--- a/include/display_properties.h
+++ b/include/display_properties.h
@@ -96,6 +96,7 @@
 #define DISABLE_EXCl_RECT_PARTIAL_FB         DISPLAY_PROP("disable_excl_rect_partial_fb")
 #define DISABLE_FBID_CACHE                   DISPLAY_PROP("disable_fbid_cache")
 #define DISABLE_HOTPLUG_BWCHECK              DISPLAY_PROP("disable_hotplug_bwcheck")
+#define DISABLE_MASK_LAYER_HINT              DISPLAY_PROP("disable_mask_layer_hint")
 
 #define DISABLE_HDR_LUT_GEN                  DISPLAY_PROP("disable_hdr_lut_gen")
 #define ENABLE_DEFAULT_COLOR_MODE            DISPLAY_PROP("enable_default_color_mode")