Remove unused param from InterpFilterParams

BUG=aomedia:2634

Change-Id: I5cd759264923d08cae19f946d72160a82e8d1b03
diff --git a/av1/common/filter.h b/av1/common/filter.h
index 91791d3..0f0da9d 100644
--- a/av1/common/filter.h
+++ b/av1/common/filter.h
@@ -102,7 +102,6 @@
 typedef struct InterpFilterParams {
   const int16_t *filter_ptr;
   uint16_t taps;
-  uint16_t subpel_shifts;
   InterpFilter interp_filter;
 } InterpFilterParams;
 
@@ -156,14 +155,12 @@
 
 static const InterpFilterParams
     av1_interp_filter_params_list[SWITCHABLE_FILTERS + 1] = {
-      { (const int16_t *)av1_sub_pel_filters_8, SUBPEL_TAPS, SUBPEL_SHIFTS,
-        EIGHTTAP_REGULAR },
+      { (const int16_t *)av1_sub_pel_filters_8, SUBPEL_TAPS, EIGHTTAP_REGULAR },
       { (const int16_t *)av1_sub_pel_filters_8smooth, SUBPEL_TAPS,
-        SUBPEL_SHIFTS, EIGHTTAP_SMOOTH },
-      { (const int16_t *)av1_sub_pel_filters_8sharp, SUBPEL_TAPS, SUBPEL_SHIFTS,
+        EIGHTTAP_SMOOTH },
+      { (const int16_t *)av1_sub_pel_filters_8sharp, SUBPEL_TAPS,
         MULTITAP_SHARP },
-      { (const int16_t *)av1_bilinear_filters, SUBPEL_TAPS, SUBPEL_SHIFTS,
-        BILINEAR }
+      { (const int16_t *)av1_bilinear_filters, SUBPEL_TAPS, BILINEAR }
     };
 
 // A special 2-tap bilinear filter for IntraBC chroma. IntraBC uses full pixel
@@ -175,7 +172,7 @@
 };
 
 static const InterpFilterParams av1_intrabc_filter_params = {
-  av1_intrabc_bilinear_filter, 2, 0, BILINEAR
+  av1_intrabc_bilinear_filter, 2, BILINEAR
 };
 
 DECLARE_ALIGNED(256, static const InterpKernel,
@@ -213,14 +210,11 @@
 
 // For w<=4, MULTITAP_SHARP is the same as EIGHTTAP_REGULAR
 static const InterpFilterParams av1_interp_4tap[SWITCHABLE_FILTERS + 1] = {
-  { (const int16_t *)av1_sub_pel_filters_4, SUBPEL_TAPS, SUBPEL_SHIFTS,
-    EIGHTTAP_REGULAR },
-  { (const int16_t *)av1_sub_pel_filters_4smooth, SUBPEL_TAPS, SUBPEL_SHIFTS,
+  { (const int16_t *)av1_sub_pel_filters_4, SUBPEL_TAPS, EIGHTTAP_REGULAR },
+  { (const int16_t *)av1_sub_pel_filters_4smooth, SUBPEL_TAPS,
     EIGHTTAP_SMOOTH },
-  { (const int16_t *)av1_sub_pel_filters_4, SUBPEL_TAPS, SUBPEL_SHIFTS,
-    EIGHTTAP_REGULAR },
-  { (const int16_t *)av1_bilinear_filters, SUBPEL_TAPS, SUBPEL_SHIFTS,
-    BILINEAR },
+  { (const int16_t *)av1_sub_pel_filters_4, SUBPEL_TAPS, EIGHTTAP_REGULAR },
+  { (const int16_t *)av1_bilinear_filters, SUBPEL_TAPS, BILINEAR },
 };
 
 static INLINE const InterpFilterParams *