Cater for preloaded BL33 within plat_get_ns_image_entrypoint()

The PRELOADED_BL33_BASE build option allows to preload a BL33 and bypass its
loading by BL2. In ARM standard platforms, the conditional behaviour of
PRELOADED_BL33_BASE is moved within the implementation of
`plat_get_ns_image_entrypoint()` so that all callers may benefit from this
feature.

Change-Id: Iea060e204ec72f8081087837854535c4e320da4e

plat/arm/common/arm_bl31_setup.c

@@ -130,11 +130,8 @@ void arm_bl31_early_platform_setup(bl31_params_t *from_bl2,
 	 * Tell BL31 where the non-trusted software image
 	 * is located and the entry state information
 	 */
-#ifdef PRELOADED_BL33_BASE
-	bl33_image_ep_info.pc = PRELOADED_BL33_BASE;
-#else
 	bl33_image_ep_info.pc = plat_get_ns_image_entrypoint();
-#endif /* PRELOADED_BL33_BASE */
+
 	bl33_image_ep_info.spsr = arm_get_spsr_for_bl33_entry();
 	SET_SECURITY_STATE(bl33_image_ep_info.h.attr, NON_SECURE);
 

plat/arm/common/arm_common.c

@@ -114,7 +114,11 @@ void arm_setup_page_tables(uintptr_t total_base,
 
 uintptr_t plat_get_ns_image_entrypoint(void)
 {
+#ifdef PRELOADED_BL33_BASE
+	return PRELOADED_BL33_BASE;
+#else
 	return PLAT_ARM_NS_IMAGE_OFFSET;
+#endif
 }
 
 /*******************************************************************************