Replace all SCP FW (BL0, BL3-0) references

This patch replaces all references to the SCP Firmware (BL0, BL30,
BL3-0, bl30) with the image terminology detailed in the TF wiki
(https://github.com/ARM-software/arm-trusted-firmware/wiki):

    BL0          -->  SCP_BL1
    BL30, BL3-0  -->  SCP_BL2
    bl30         -->  scp_bl2

This change affects code, documentation, build system, tools and
platform ports that load SCP firmware. ARM plaforms have been
updated to the new porting API.

IMPORTANT: build option to specify the SCP FW image has changed:

    BL30 --> SCP_BL2

IMPORTANT: This patch breaks compatibility for platforms that use BL2
to load SCP firmware. Affected platforms must be updated as follows:

    BL30_IMAGE_ID --> SCP_BL2_IMAGE_ID
    BL30_BASE --> SCP_BL2_BASE
    bl2_plat_get_bl30_meminfo() --> bl2_plat_get_scp_bl2_meminfo()
    bl2_plat_handle_bl30() --> bl2_plat_handle_scp_bl2()

Change-Id: I24c4c1a4f0e4b9f17c9e4929da815c4069549e58
diff --git a/plat/arm/css/common/css_scp_bootloader.c b/plat/arm/css/common/css_scp_bootloader.c
index acc7351..c01f42f 100644
--- a/plat/arm/css/common/css_scp_bootloader.c
+++ b/plat/arm/css/common/css_scp_bootloader.c
@@ -118,10 +118,10 @@
 	cmd_info_payload_t *cmd_info_payload;
 	cmd_data_payload_t *cmd_data_payload;
 
-	assert((uintptr_t) image == BL30_BASE);
+	assert((uintptr_t) image == SCP_BL2_BASE);
 
 	if ((image_size == 0) || (image_size % 4 != 0)) {
-		ERROR("Invalid size for the BL3-0 image. Must be a multiple of "
+		ERROR("Invalid size for the SCP_BL2 image. Must be a multiple of "
 			"4 bytes and not zero (current size = 0x%x)\n",
 			image_size);
 		return -1;
@@ -134,7 +134,7 @@
 
 	mhu_secure_init();
 
-	VERBOSE("Send info about the BL3-0 image to be transferred to SCP\n");
+	VERBOSE("Send info about the SCP_BL2 image to be transferred to SCP\n");
 
 	/*
 	 * Send information about the SCP firmware image about to be transferred
@@ -174,9 +174,9 @@
 		return -1;
 	}
 
-	VERBOSE("Transferring BL3-0 image to SCP\n");
+	VERBOSE("Transferring SCP_BL2 image to SCP\n");
 
-	/* Transfer BL3-0 image to SCP */
+	/* Transfer SCP_BL2 image to SCP */
 	scp_boot_message_start();
 
 	BOM_CMD_HEADER->id = BOOT_CMD_DATA;