BaseTools/tools_def GCC: ARM/AARCH64: drop -save-temps from command line

BaseTools/tools_def GCC: ARM/AARCH64: drop -save-temps from command line

For historical reasons, GCC builds for ARM and AARCH64 pass the
-save-temps command line option to GCC, which instructs the compiler
to preserve intermediate files, i.e., preprocessor output and generated
assembler. Given that this clutters up the Build directory, and slows
down the build, let's remove it.

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