Seperate FILTER_INTRA from EXT_INTRA experiment

Prepare for the av1/nextgenv2 merge.

Coding gain (%):

               lowres     midres
ext-intra       0.69       0.97
filter-intra    0.67       0.83
both            1.05       1.48

Change-Id: Ia24d6fafb3e484c4f92192e0b7eee5e39f4f4ee6

av1/common/av1_rtcd_defs.pl

diff --git a/av1/common/av1_rtcd_defs.pl b/av1/common/av1_rtcd_defs.pl
index 3e1b02f..53c9dc5 100644
--- a/av1/common/av1_rtcd_defs.pl
+++ b/av1/common/av1_rtcd_defs.pl
@@ -199,8 +199,8 @@
   specialize qw/quantize_32x32_fp_nuq/;
 }
 
-# EXT_INTRA predictor functions
-if (aom_config("CONFIG_EXT_INTRA") eq "yes") {
+# FILTER_INTRA predictor functions
+if (aom_config("CONFIG_FILTER_INTRA") eq "yes") {
   add_proto qw/void av1_dc_filter_predictor/, "uint8_t *dst, ptrdiff_t stride, int bs, const uint8_t *above, const uint8_t *left";
   specialize qw/av1_dc_filter_predictor sse4_1/;
   add_proto qw/void av1_v_filter_predictor/, "uint8_t *dst, ptrdiff_t stride, int bs, const uint8_t *above, const uint8_t *left";