Add a SB QP offset option for perceptual quality tuning

Add an option to allow SB level QP offset for all intra frame
perceptual quality tuning.

Change-Id: I0ce5054c1c7627c0a5a00caf8a8623c4be9add29
diff --git a/av1/encoder/encoder.h b/av1/encoder/encoder.h
index a9dca94..5d84232 100644
--- a/av1/encoder/encoder.h
+++ b/av1/encoder/encoder.h
@@ -150,9 +150,10 @@
 } UENUM1BYTE(AQ_MODE);
 enum {
   NO_DELTA_Q = 0,
-  DELTA_Q_OBJECTIVE = 1,   // Modulation to improve objective quality
-  DELTA_Q_PERCEPTUAL = 2,  // Modulation to improve perceptual quality
-  DELTA_Q_MODE_COUNT       // This should always be the last member of the enum
+  DELTA_Q_OBJECTIVE = 1,      // Modulation to improve objective quality
+  DELTA_Q_PERCEPTUAL = 2,     // Modulation to improve video perceptual quality
+  DELTA_Q_PERCEPTUAL_AI = 3,  // Perceptual quality opt for all intra mode
+  DELTA_Q_MODE_COUNT  // This should always be the last member of the enum
 } UENUM1BYTE(DELTAQ_MODE);
 
 enum {