Fix libvpx clang build

64-bit clang builds with ninja were failing because LOCAL_CLANG_ASFLAGS
was set to always point to the intermediates directory for the primary
architecture.  Ninja happens to build the secondary architecture first,
and if the translated assembly for the primary architecture hasn't been
built yet it results in:
out/target/product/flounder/obj_arm/STATIC_LIBRARIES/libvpx_intermediates/vp8/encoder/arm/neon/subtract_neon.asm.s: Assembler messages:
out/target/product/flounder/obj_arm/STATIC_LIBRARIES/libvpx_intermediates/vp8/encoder/arm/neon/subtract_neon.asm.s:21: Error: can't open vp8_asm_enc_offsets.asm for reading: No such file or directory

Modify libvpx.mk to use the primary intermediates for the primary
architecture and the secondary intermediates for the secondary architecture.

Change-Id: I3bf6e63e846ad5985b2f46f72995664e183de394
1 file changed