build/make/iosbuild.sh: Remove armv6 support.

Apple no longer supports armv6 targets in Xcode or iOS.

Change-Id: Ia7aa496afe62162c43c004530324406486c9a052

build/make/iosbuild.sh

@@ -26,7 +26,6 @@ LIBVPX_SOURCE_DIR=$(dirname "$0" | sed -e s,/build/make,,)
 LIPO=$(xcrun -sdk iphoneos${SDK} -find lipo)
 ORIG_PWD="$(pwd)"
 TARGETS="arm64-darwin-gcc
-         armv6-darwin-gcc
          armv7-darwin-gcc
          armv7s-darwin-gcc
          x86-iphonesimulator-gcc