BaseTools CLANG35: add missing XIP flags for AARCH64

BaseTools CLANG35: add missing XIP flags for AARCH64

When building for AARCH64, code that may execute with the MMU off should
not perform unaligned accesses, which is why we set -mstrict-align for
BASE, SEC, PEI_CORE and PEIM modules when building with GCCx. However,
this setting is missing from CLANG35 so set it there as well.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Liming Gao <liming.gao@intel.com>