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/plat/arm/board/fvp/include/plat_macros.S b/plat/arm/board/fvp/include/plat_macros.S
index 2ed0d85..2117843 100644
--- a/plat/arm/board/fvp/include/plat_macros.S
+++ b/plat/arm/board/fvp/include/plat_macros.S
@@ -37,7 +37,7 @@
 	/* ---------------------------------------------
 	 * The below required platform porting macro
 	 * prints out relevant GIC registers whenever an
-	 * unhandled exception is taken in BL3-1.
+	 * unhandled exception is taken in BL31.
 	 * Clobbers: x0 - x10, x16, x17, sp
 	 * ---------------------------------------------
 	 */