sdm: Defer vsync enable/disable when display is powered off

DRM framework rejects vsync enable/disable request when it is requested
before display is powered on. Hence defer the request after display is
powered on.

Change-Id: I3063479c8efc03d87f736a069ad742ae18296fd5
diff --git a/include/display_properties.h b/include/display_properties.h
index 8b0ab16..a5c1378 100644
--- a/include/display_properties.h
+++ b/include/display_properties.h
@@ -121,6 +121,7 @@
 #define VIRTUAL_BASEID_AND_SIZE_PROP         DISPLAY_PROP("virtual_baseid_and_size")
 #define ENABLE_QDCM_DIAG                     DISPLAY_PROP("enable_qdcm_diag")
 #define QDCM_DISABLE_FACTORY_MODE_PROP       DISPLAY_PROP("qdcm.disable_factory_mode")
+#define DISABLE_DEFER_POWER_STATE            DISPLAY_PROP("disable_defer_power_state")
 
 #define ZERO_SWAP_INTERVAL                   "vendor.debug.egl.swapinterval"
 #define ENABLE_OPTIMIZE_REFRESH              DISPLAY_PROP("enable_optimize_refresh")