Update libvpx snapshot to v0.9.7-p1 (Cayuga).

source/libvpx/vp8/decoder/arm/neon/dequant_idct_neon.asm

 ;
 ;  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
 ;
 ;  Use of this source code is governed by a BSD-style license
 ;  that can be found in the LICENSE file in the root of the source
 ;  tree. An additional intellectual property rights grant can be found
 ;  in the file PATENTS.  All contributing project authors may
 ;  be found in the AUTHORS file in the root of the source tree.
 ;
 
@@ skipping 17 matching lines @@
     vld1.16         {q3, q4}, [r0]
     vld1.16         {q5, q6}, [r1]
     ldr             r1, [sp]                ; pitch
     vld1.32         {d14[0]}, [r2], r1
     vld1.32         {d14[1]}, [r2], r1
     vld1.32         {d15[0]}, [r2], r1
     vld1.32         {d15[1]}, [r2]
 
     ldr             r1, [sp, #4]            ; stride
 
-    ldr             r12, _CONSTANTS_
+    adr             r12, cospi8sqrt2minus1  ; pointer to the first constant
 
     vmul.i16        q1, q3, q5              ;input for short_idct4x4llm_neon
     vmul.i16        q2, q4, q6
 
 ;|short_idct4x4llm_neon| PROC
     vld1.16         {d0}, [r12]
     vswp            d3, d4                  ;q2(vp[4] vp[12])
 
     vqdmulh.s16     q3, q2, d0[2]
     vqdmulh.s16     q4, q2, d0[0]
@@ skipping 67 matching lines @@
     vst1.32         {d0[0]}, [r3], r1
     vst1.32         {d0[1]}, [r3], r1
     vst1.32         {d1[0]}, [r3], r1
     vst1.32         {d1[1]}, [r3]
 
     bx             lr
 
     ENDP           ; |vp8_dequant_idct_add_neon|
 
 ; Constant Pool
-_CONSTANTS_       DCD cospi8sqrt2minus1
 cospi8sqrt2minus1 DCD 0x4e7b4e7b
 sinpi8sqrt2       DCD 0x8a8c8a8c
 
     END