AArch32: Add ARM platform changes in BL2

This patch adds ARM platform changes in BL2 for AArch32 state.
It instantiates a descriptor array for ARM platforms describing
image and entrypoint information for `SCP_BL2`, `BL32` and `BL33`.
It also enables building of BL2 for ARCH=aarch32.

Change-Id: I60dc7a284311eceba401fc789311c50ac746c51e
diff --git a/plat/arm/common/arm_bl2_setup.c b/plat/arm/common/arm_bl2_setup.c
index a2ae11a..a4fac0d 100644
--- a/plat/arm/common/arm_bl2_setup.c
+++ b/plat/arm/common/arm_bl2_setup.c
@@ -246,7 +246,12 @@
 			      BL2_COHERENT_RAM_LIMIT
 #endif
 			      );
+
+#ifdef AARCH32
+	enable_mmu_secure(0);
+#else
 	enable_mmu_el1(0);
+#endif
 }
 
 void bl2_plat_arch_setup(void)
@@ -266,9 +271,11 @@
 	assert(bl_mem_params);
 
 	switch (image_id) {
+#ifdef AARCH64
 	case BL32_IMAGE_ID:
 		bl_mem_params->ep_info.spsr = arm_get_spsr_for_bl32_entry();
 		break;
+#endif
 
 	case BL33_IMAGE_ID:
 		/* BL33 expects to receive the primary CPU MPID (through r0) */