Rename ARM public symbol that collides with libvpx.

When building for ARM, the exposed arm_cpu_caps() collides with the same
 function in libvpx. This renames it to aom_arm_cpu_caps().

BUG=aomedia:1540

Change-Id: I8869dba71b345cf55f32a316c6d1de43debd6b3d

aom_ports/arm.h

diff --git a/aom_ports/arm.h b/aom_ports/arm.h
index 1aade74..cb1fb9b 100644
--- a/aom_ports/arm.h
+++ b/aom_ports/arm.h
@@ -26,7 +26,7 @@
 /*ARMv7 optional NEON instructions.*/
 #define HAS_NEON 0x04
 
-int arm_cpu_caps(void);
+int aom_arm_cpu_caps(void);
 
 // Earlier gcc compilers have issues with some neon intrinsics
 #if !defined(__clang__) && defined(__GNUC__) && __GNUC__ == 4 && \

aom_ports/arm_cpudetect.c

diff --git a/aom_ports/arm_cpudetect.c b/aom_ports/arm_cpudetect.c
index 70efee9..5a75bb3 100644
--- a/aom_ports/arm_cpudetect.c
+++ b/aom_ports/arm_cpudetect.c
@@ -40,7 +40,7 @@
 
 #if !CONFIG_RUNTIME_CPU_DETECT
 
-int arm_cpu_caps(void) {
+int aom_arm_cpu_caps(void) {
   /* This function should actually be a no-op. There is no way to adjust any of
    * these because the RTCD tables do not exist: the functions are called
    * statically */
@@ -62,7 +62,7 @@
 #define WIN32_EXTRA_LEAN
 #include <windows.h>
 
-int arm_cpu_caps(void) {
+int aom_arm_cpu_caps(void) {
   int flags;
   int mask;
   if (!arm_cpu_env_flags(&flags)) {
@@ -90,7 +90,7 @@
 #elif defined(__ANDROID__) /* end _MSC_VER */
 #include <cpu-features.h>
 
-int arm_cpu_caps(void) {
+int aom_arm_cpu_caps(void) {
   int flags;
   int mask;
   uint64_t features;
@@ -110,7 +110,7 @@
 
 #include <stdio.h>
 
-int arm_cpu_caps(void) {
+int aom_arm_cpu_caps(void) {
   FILE *fin;
   int flags;
   int mask;

build/cmake/rtcd.pl

diff --git a/build/cmake/rtcd.pl b/build/cmake/rtcd.pl
index a71a92c..46e0690 100755
--- a/build/cmake/rtcd.pl
+++ b/build/cmake/rtcd.pl
@@ -304,7 +304,7 @@
 #include "aom_ports/arm.h"
 static void setup_rtcd_internal(void)
 {
-    int flags = arm_cpu_caps();
+    int flags = aom_arm_cpu_caps();
 
     (void)flags;