Merge pull request #924 from antonio-nino-diaz-arm/an/fix-xn-bit

Fix execute-never permissions in xlat tables libs

diff --cc include/lib/xlat_tables/xlat_tables_defs.h
Simple merge

diff --cc lib/xlat_tables/aarch32/xlat_tables.c
Simple merge

diff --cc lib/xlat_tables/aarch64/xlat_tables.c
Simple merge

diff --cc lib/xlat_tables/xlat_tables_common.c
Simple merge

diff --cc lib/xlat_tables/xlat_tables_private.h
Simple merge

diff --cc lib/xlat_tables_v2/aarch32/xlat_tables_arch.c
Simple merge

diff --cc lib/xlat_tables_v2/aarch64/xlat_tables_arch.c
Simple merge

diff --cc lib/xlat_tables_v2/xlat_tables_common.c
Simple merge

diff --cc lib/xlat_tables_v2/xlat_tables_internal.c
Simple merge

diff --cc lib/xlat_tables_v2/xlat_tables_private.h
Simple merge