Homogenize configuration option name.

Rename '--enable-aom-highbitdepth' to '--enable-highbitdepth'

Change-Id: I1de13c3508c30c552532993419d8ace326142ab6
diff --git a/av1/encoder/ratectrl.c b/av1/encoder/ratectrl.c
index 56eae7e..2e31699 100644
--- a/av1/encoder/ratectrl.c
+++ b/av1/encoder/ratectrl.c
@@ -43,7 +43,7 @@
 #define MAX_BPB_FACTOR 50
 
 #define FRAME_OVERHEAD_BITS 200
-#if CONFIG_AOM_HIGHBITDEPTH
+#if CONFIG_HIGHBITDEPTH
 #define ASSIGN_MINQ_TABLE(bit_depth, name)                   \
   do {                                                       \
     switch (bit_depth) {                                     \
@@ -73,7 +73,7 @@
 static int inter_minq_8[QINDEX_RANGE];
 static int rtc_minq_8[QINDEX_RANGE];
 
-#if CONFIG_AOM_HIGHBITDEPTH
+#if CONFIG_HIGHBITDEPTH
 static int kf_low_motion_minq_10[QINDEX_RANGE];
 static int kf_high_motion_minq_10[QINDEX_RANGE];
 static int arfgf_low_motion_minq_10[QINDEX_RANGE];
@@ -132,7 +132,7 @@
   init_minq_luts(kf_low_motion_minq_8, kf_high_motion_minq_8,
                  arfgf_low_motion_minq_8, arfgf_high_motion_minq_8,
                  inter_minq_8, rtc_minq_8, AOM_BITS_8);
-#if CONFIG_AOM_HIGHBITDEPTH
+#if CONFIG_HIGHBITDEPTH
   init_minq_luts(kf_low_motion_minq_10, kf_high_motion_minq_10,
                  arfgf_low_motion_minq_10, arfgf_high_motion_minq_10,
                  inter_minq_10, rtc_minq_10, AOM_BITS_10);
@@ -147,7 +147,7 @@
 // tables if and when things settle down in the experimental bitstream
 double av1_convert_qindex_to_q(int qindex, aom_bit_depth_t bit_depth) {
 // Convert the index to a real Q value (scaled down to match old Q values)
-#if CONFIG_AOM_HIGHBITDEPTH
+#if CONFIG_HIGHBITDEPTH
   switch (bit_depth) {
     case AOM_BITS_8: return av1_ac_quant(qindex, 0, bit_depth) / 4.0;
     case AOM_BITS_10: return av1_ac_quant(qindex, 0, bit_depth) / 16.0;