amlogic: Fix prefixes in the MHU code

Make the MHU code AML specific adding a new aml_* prefix and remove the
GXBB prefix from the register names.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
Change-Id: I8f20918e29f08542bd71bd679f88e65b4efaa7d2
diff --git a/plat/amlogic/gxbb/gxbb_bl31_setup.c b/plat/amlogic/gxbb/gxbb_bl31_setup.c
index cff29b3..26419d4 100644
--- a/plat/amlogic/gxbb/gxbb_bl31_setup.c
+++ b/plat/amlogic/gxbb/gxbb_bl31_setup.c
@@ -135,7 +135,7 @@
 
 void bl31_platform_setup(void)
 {
-	mhu_secure_init();
+	aml_mhu_secure_init();
 
 	gicv2_driver_init(&gxbb_gic_data);
 	gicv2_distif_init();