Declare final_filter_fast_internal as static.

final_filter_fast_internal is only used within this file.

Change-Id: Ib95733d8496880fef4004ad5b1f3a29b298710bd

av1/common/arm/selfguided_neon.c

diff --git a/av1/common/arm/selfguided_neon.c b/av1/common/arm/selfguided_neon.c
index b4808a9..d139efe 100644
--- a/av1/common/arm/selfguided_neon.c
+++ b/av1/common/arm/selfguided_neon.c
@@ -1007,10 +1007,11 @@
       vaddq_u32(vmovl_u16(vget_high_u16(xl)), vmovl_u16(vget_high_u16(x))));
 }
 
-void final_filter_fast_internal(uint16_t *A, int32_t *B, const int buf_stride,
-                                int16_t *src, const int src_stride,
-                                int32_t *dst, const int dst_stride,
-                                const int width, const int height) {
+static void final_filter_fast_internal(uint16_t *A, int32_t *B,
+                                       const int buf_stride, int16_t *src,
+                                       const int src_stride, int32_t *dst,
+                                       const int dst_stride, const int width,
+                                       const int height) {
   int16x8_t s0;
   int32_t *B_tmp, *dst_ptr;
   uint16_t *A_tmp;