AArch32: Add ARM platform changes in BL1

This patch adds ARM platform changes in BL1 for AArch32 state.
It also enables building of BL1 for ARCH=aarch32.

Change-Id: I079be81a93d027f37b0f7d8bb474b1252bb4cf48
diff --git a/Makefile b/Makefile
index 15b1ac8..aaf84db 100644
--- a/Makefile
+++ b/Makefile
@@ -517,13 +517,13 @@
 ################################################################################
 # Include BL specific makefiles
 ################################################################################
-# BL31 is not needed and BL1, BL2 & BL2U are not currently supported in AArch32
-ifneq (${ARCH},aarch32)
 ifdef BL1_SOURCES
 NEED_BL1 := yes
 include bl1/bl1.mk
 endif
 
+# For AArch32, BL31 is not applicable, and BL2 & BL2U are not supported at present.
+ifneq (${ARCH},aarch32)
 ifdef BL2_SOURCES
 NEED_BL2 := yes
 include bl2/bl2.mk