fix(xlat): fix defects on the xlat library reported by coverity scan

The coverity defects fixed by this patch is

** CID 394601:  Integer handling issues  (NO_EFFECT)
/lib/xlat_tables_v2/aarch64/xlat_tables_arch.c: 30 in
xlat_arch_is_granule_size_supported()

Signed-off-by: Javier Almansa Sobrino <javier.almansasobrino@arm.com>
Change-Id: Ibc8e20bd7318a52702fbd7aa86e22cd2ded42610
1 file changed