Add aarch64 support in files/Makefile (#153)
Add aarch64 support in files/Makefile (#153)

In files/Makefile, the aarch64 does not well supportted by Istio.
In this patch, aarch64 option is added in files/Makefile.

Signed-off-by: Jingzhao <fbcdccead3fe6b8b622287f73a59e6a4f4b59a50@arm.com>
istio/common-files,istio/common-files