fix(build): allow gcc linker on Aarch32 platforms

When trying to compile and link with gcc on an Aarch32 platform, there
is the following error:
arm-none-eabi-gcc: error: unrecognized command-line option
 '-mno-fix-cortex-a53-843419'; did you mean '-mno-fix-cortex-m3-ldrd'?

This option seems specific to Aarch64 version of GCC.
Enclose it with a check on ARCH=aarch64.

Signed-off-by: Yann Gautier <yann.gautier@st.com>
Change-Id: I8c8cb784ce2f2938c4c6999745dda09ee9a5669d
1 file changed