arch: arm: Add support to conditionally include identity mmu mappings.

Change-Id: Ic1bbea9908c3ddab0160ee9db5aa98a1ac61f248
diff --git a/platform/init.c b/platform/init.c
index 4188f27..30f3e51 100644
--- a/platform/init.c
+++ b/platform/init.c
@@ -28,11 +28,29 @@
  * default implementations of these routines, if the platform code
  * chooses not to implement.
  */
+__WEAK int platform_use_identity_mmu_mappings(void)
+{
+	return 1;
+}
 
 __WEAK void platform_init_mmu_mappings(void)
 {
 }
 
+__WEAK addr_t platform_get_virt_to_phys_mapping(addr_t virt_addr)
+{
+	ASSERT(platform_use_identity_mmu_mappings());
+
+	return virt_addr;
+}
+
+__WEAK addr_t platform_get_phys_to_virt_mapping(addr_t phys_addr)
+{
+	ASSERT(platform_use_identity_mmu_mappings());
+
+	return phys_addr;
+}
+
 __WEAK void platform_early_init(void)
 {
 }