target/s390x: Mark STFLE_53 facility as available

This facility bit includes load-on-condition-2 and
load-and-zero-rightmost-byte.

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c
index e676d7d..c55823b 100644
--- a/target/s390x/cpu_models.c
+++ b/target/s390x/cpu_models.c
@@ -687,6 +687,7 @@
         S390_FEAT_EXECUTE_EXT,
         S390_FEAT_FLOATING_POINT_SUPPPORT_ENH,
         S390_FEAT_STFLE_45,
+        S390_FEAT_STFLE_53,
     };
     int i;