Fix building errors when enhanced skip mode is off

For issue #141.
diff --git a/av1/common/entropymode.c b/av1/common/entropymode.c
index abb1988..ef462a7 100644
--- a/av1/common/entropymode.c
+++ b/av1/common/entropymode.c
@@ -2414,7 +2414,7 @@
 };
 
 #endif  // CONFIG_NEW_CONTEXT_MODELING
-#if CONFIG_SKIP_MODE_ENHANCEMENT
+
 #if CONFIG_NEW_CONTEXT_MODELING
 static const aom_cdf_prob default_skip_mode_cdfs[SKIP_MODE_CONTEXTS][CDF_SIZE(
     2)] = { { AOM_CDF2(32298) }, { AOM_CDF2(23079) }, { AOM_CDF2(7376) } };
@@ -2422,7 +2422,6 @@
 static const aom_cdf_prob default_skip_mode_cdfs[SKIP_MODE_CONTEXTS][CDF_SIZE(
     2)] = { { AOM_CDF2(32621) }, { AOM_CDF2(20708) }, { AOM_CDF2(8127) } };
 #endif
-#endif  // CONFIG_SKIP_MODE_ENHANCEMENT
 
 #if CONFIG_NEW_CONTEXT_MODELING
 static const aom_cdf_prob
diff --git a/av1/common/mvref_common.c b/av1/common/mvref_common.c
index 7851940..36d7d75 100644
--- a/av1/common/mvref_common.c
+++ b/av1/common/mvref_common.c
@@ -1427,13 +1427,15 @@
                           int *added_tmvp_cnt,
 #endif  // CONFIG_C063_TMVP_IMPROVEMENT
                           CANDIDATE_MV ref_mv_stack[MAX_REF_MV_STACK_SIZE],
-                          uint16_t ref_mv_weight[MAX_REF_MV_STACK_SIZE],
+                          uint16_t ref_mv_weight[MAX_REF_MV_STACK_SIZE]
 #if CONFIG_SKIP_MODE_DRL_WITH_REF_IDX
+                          ,
                           MV_REFERENCE_FRAME *ref_frame_idx0,
                           MV_REFERENCE_FRAME *ref_frame_idx1
 #endif  // CONFIG_SKIP_MODE_DRL_WITH_REF_IDX
 #if !CONFIG_C076_INTER_MOD_CTX
-                              int16_t *mode_context
+                          ,
+                          int16_t *mode_context
 #endif  // !CONFIG_C076_INTER_MOD_CTX
 ) {
   POSITION mi_pos;
@@ -2148,8 +2150,9 @@
 #if CONFIG_C063_TMVP_IMPROVEMENT
                            &added_tmvp_cnt,
 #endif  // CONFIG_C063_TMVP_IMPROVEMENT
-                           ref_mv_stack, ref_mv_weight,
+                           ref_mv_stack, ref_mv_weight
 #if CONFIG_SKIP_MODE_DRL_WITH_REF_IDX
+                           ,
                            ref_frame_idx0, ref_frame_idx1
 #endif  // CONFIG_SKIP_MODE_DRL_WITH_REF_IDX
 #if !CONFIG_C076_INTER_MOD_CTX