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/bl1/bl1_main.c b/bl1/bl1_main.c
index 84d5611..3cca176 100644
--- a/bl1/bl1_main.c
+++ b/bl1/bl1_main.c
@@ -216,7 +216,7 @@
  ******************************************************************************/
 void bl1_print_bl31_ep_info(const entry_point_info_t *bl31_ep_info)
 {
-	NOTICE("BL1: Booting BL3-1\n");
+	NOTICE("BL1: Booting BL31\n");
 	print_entry_point_info(bl31_ep_info);
 }