some fixes for android build script.
remove armv6,x86 options and add "android_arch" option for select
compiler architecture (armv7,armv6,x86)(default armv7).
add architecture suffix for output files and you can compile for several
architecture simultaneously.
example:
libgodot.android.opt.debug.armv7.so
libgodot.android.opt.debug.armv7.neon.so
libgodot.android.opt.debug.armv6.so
libgodot.android.opt.debug.x86.so
now we can enable/disable neon on armv7 with "android_neon" option
(default enable).
add "NDK_TARGET_X86" option for select toolchain to use for the NDK x86
(default x86-4.8).
change inputs model for "ndk_platform" option (default android-15).
fix armv7 ccflags.
with this patch, must put libgodot_android.so file in specific
architecture folder:
armv7 (default): <android-java>/libs/armeabi-v7a/
armv6: <android-java>/libs/armeabi/
x86: <android-java>/libs/x86/
