Remove dashes from image names: 'BL3-x' --> 'BL3x'

This patch removes the dash character from the image name, to
follow the image terminology in the Trusted Firmware Wiki page:

    https://github.com/ARM-software/arm-trusted-firmware/wiki

Changes apply to output messages, comments and documentation.

non-ARM platform files have been left unmodified.

Change-Id: Ic2a99be4ed929d52afbeb27ac765ceffce46ed76
diff --git a/Makefile b/Makefile
index 97fa0ac..b035301 100644
--- a/Makefile
+++ b/Makefile
@@ -309,7 +309,7 @@
         CFLAGS		+= 	-pedantic
 endif
 
-# Using the ARM Trusted Firmware BL2 implies that a BL3-3 image also need to be
+# Using the ARM Trusted Firmware BL2 implies that a BL33 image also need to be
 # supplied for the FIP and Certificate generation tools. This flag can be
 # overridden by the platform.
 ifdef BL2_SOURCES
@@ -589,8 +589,8 @@
 	@echo "  bl1            Build the BL1 binary"
 	@echo "  bl2            Build the BL2 binary"
 	@echo "  bl2u           Build the BL2U binary"
-	@echo "  bl31           Build the BL3-1 binary"
-	@echo "  bl32           Build the BL3-2 binary"
+	@echo "  bl31           Build the BL31 binary"
+	@echo "  bl32           Build the BL32 binary"
 	@echo "  certificates   Build the certificates (requires 'GENERATE_COT=1')"
 	@echo "  fip            Build the Firmware Image Package (FIP)"
 	@echo "  fwu_fip        Build the FWU Firmware Image Package (FIP)"