libvpx: Pull from upstream

source/libvpx/build/make/rtcd.pl

Index: source/libvpx/build/make/rtcd.pl
===================================================================
--- source/libvpx/build/make/rtcd.pl	(revision 271012)
+++ source/libvpx/build/make/rtcd.pl	(working copy)
@@ -272,6 +272,9 @@
   # Assign the helper variable for each enabled extension
   foreach my $opt (@ALL_ARCHS) {
     my $opt_uc = uc $opt;
+    # Enable neon assembly based on HAVE_NEON logic instead of adding new
+    # HAVE_NEON_ASM logic
+    if ($opt eq 'neon_asm') { $opt_uc = 'NEON' }
     eval "\$have_${opt}=\"flags & HAS_${opt_uc}\"";
   }
 
@@ -381,8 +384,11 @@
   @ALL_ARCHS = filter(qw/edsp media/);
   arm;
 } elsif ($opts{arch} eq 'armv7') {
-  @ALL_ARCHS = filter(qw/edsp media neon/);
+  @ALL_ARCHS = filter(qw/edsp media neon_asm neon/);
   arm;
+} elsif ($opts{arch} eq 'armv8') {
+  @ALL_ARCHS = filter(qw/neon/);
+  arm;
 } else {
   unoptimized;
 }