sdm: Add Color Interface for Snapdragon Display Manager

1. Adds color interface to color service.
2. Adds data structure shared between color service and SDM.

Change-Id: I164992d61dc750f23bd54877520ae8c9966ec446
diff --git a/sdm/include/utils/constants.h b/sdm/include/utils/constants.h
index b68604d..bf5a916 100644
--- a/sdm/include/utils/constants.h
+++ b/sdm/include/utils/constants.h
@@ -53,6 +53,8 @@
 #define CLEAR_BIT(value, bit) (value &= (~(1 << (bit))))
 #define IS_BIT_SET(value, bit) (value & (1 << (bit)))
 
+#define BITMAP(bit) (1 << (bit))
+
 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
 #define MIN(a, b) (((a) < (b)) ? (a) : (b))