uniphier: use enable_mmu() in common function

Currently, enable_mmu_el1() or enable_mmu_el3() is kept outside the
common function because the appropriate one must be chosen.

Use enable_mmu() and move it to the common function.

Change-Id: If2fb651691a7b6be05674f5cf730ae067ba95d4b
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/plat/socionext/uniphier/uniphier_xlat_setup.c b/plat/socionext/uniphier/uniphier_xlat_setup.c
index 66c7834..c2ac7a2 100644
--- a/plat/socionext/uniphier/uniphier_xlat_setup.c
+++ b/plat/socionext/uniphier/uniphier_xlat_setup.c
@@ -63,4 +63,6 @@
 			MT_DEVICE | MT_RW | MT_SECURE);
 
 	init_xlat_tables();
+
+	enable_mmu(0);
 }