convolve neon: hide unused functions

Only build Nx1 versions when not targeting aarch64

Originally added in fcb3eea and e4deec

Change-Id: I69e384c3bc920a6b82c5e932b8b9759cbb9b9181
diff --git a/av1/common/arm/convolve_neon.c b/av1/common/arm/convolve_neon.c
index 93dccc8..a0bb32e 100644
--- a/av1/common/arm/convolve_neon.c
+++ b/av1/common/arm/convolve_neon.c
@@ -68,6 +68,7 @@
   return vqmovun_s16(sum);
 }
 
+#if !defined(__aarch64__)
 static INLINE uint8x8_t convolve8_horiz_4x1(
     const int16x4_t s0, const int16x4_t s1, const int16x4_t s2,
     const int16x4_t s3, const int16x4_t s4, const int16x4_t s5,
@@ -92,6 +93,7 @@
 
   return vqmovun_s16(vcombine_s16(sum, sum));
 }
+#endif  // !defined(__arch64__)
 
 static INLINE uint8x8_t convolve8_vert_8x4(
     const int16x8_t s0, const int16x8_t s1, const int16x8_t s2,
diff --git a/av1/common/arm/jnt_convolve_neon.c b/av1/common/arm/jnt_convolve_neon.c
index 0bc9d92..620c784 100644
--- a/av1/common/arm/jnt_convolve_neon.c
+++ b/av1/common/arm/jnt_convolve_neon.c
@@ -22,6 +22,7 @@
 #include "av1/common/arm/mem_neon.h"
 #include "av1/common/arm/transpose_neon.h"
 
+#if !defined(__aarch64__)
 static INLINE void compute_avg_4x1(uint16x4_t res0, uint16x4_t d0,
                                    const uint16_t fwd_offset,
                                    const uint16_t bck_offset,
@@ -115,6 +116,7 @@
     *t0 = vqmovun_s16(f0);
   }
 }
+#endif  // !defined(__arch64__)
 
 static INLINE void compute_avg_4x4(
     uint16x4_t res0, uint16x4_t res1, uint16x4_t res2, uint16x4_t res3,