libvpx: Pull from upstream

source/libvpx/vp8/common/arm/neon/dc_only_idct_add_neon.asm

-;
-;  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
-;
-;  Use of this source code is governed by a BSD-style license and patent
-;  grant that can be found in the LICENSE file in the root of the source
-;  tree. All contributing project authors may be found in the AUTHORS
-;  file in the root of the source tree.
-;
-
-
-    EXPORT  |vp8_dc_only_idct_add_neon|
-    ARM
-    REQUIRE8
-    PRESERVE8
-
-    AREA ||.text||, CODE, READONLY, ALIGN=2
-
-;void vp8_dc_only_idct_add_c(short input_dc, unsigned char *pred_ptr,
-;                            int pred_stride, unsigned char *dst_ptr,
-;                            int dst_stride)
-
-; r0  input_dc
-; r1  pred_ptr
-; r2  pred_stride
-; r3  dst_ptr
-; sp  dst_stride
-
-|vp8_dc_only_idct_add_neon| PROC
-    add             r0, r0, #4
-    asr             r0, r0, #3
-    ldr             r12, [sp]
-    vdup.16         q0, r0
-
-    vld1.32         {d2[0]}, [r1], r2
-    vld1.32         {d2[1]}, [r1], r2
-    vld1.32         {d4[0]}, [r1], r2
-    vld1.32         {d4[1]}, [r1]
-
-    vaddw.u8        q1, q0, d2
-    vaddw.u8        q2, q0, d4
-
-    vqmovun.s16     d2, q1
-    vqmovun.s16     d4, q2
-
-    vst1.32         {d2[0]}, [r3], r12
-    vst1.32         {d2[1]}, [r3], r12
-    vst1.32         {d4[0]}, [r3], r12
-    vst1.32         {d4[1]}, [r3]
-
-    bx              lr
-
-    ENDP
-
-    END