doc: fwu: make changes to reflect support for FWU metadata v2

The FWU Update Agent in U-Boot supports both versions of the FWU
metadata. Make changes in the documentation to reflect this.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Tested-by: Michal Simek <michal.simek@amd.com>
diff --git a/doc/board/socionext/developerbox.rst b/doc/board/socionext/developerbox.rst
index 46712c3..863761c 100644
--- a/doc/board/socionext/developerbox.rst
+++ b/doc/board/socionext/developerbox.rst
@@ -116,6 +116,7 @@
  CONFIG_FWU_NUM_BANKS=2
  CONFIG_FWU_NUM_IMAGES_PER_BANK=1
  CONFIG_CMD_FWU_METADATA=y
+ CONFIG_FWU_MDATA_V2=y
 
 And build it::
 
@@ -129,7 +130,9 @@
 By default, the CONFIG_FWU_NUM_BANKS and CONFIG_FWU_NUM_IMAGES_PER_BANKS are
 set to 2 and 1 respectively. This uses FIP (Firmware Image Package) type image
 which contains TF-A, U-Boot and OP-TEE (the OP-TEE is optional).
-You can use fiptool to compose the FIP image from those firmware images.
+You can use fiptool to compose the FIP image from those firmware
+images. There are two versions of the FWU metadata, of which the
+platform enables version 2 by default.
 
 Rebuild SCP firmware
 --------------------
@@ -194,7 +197,7 @@
 
 These UUIDs are used for making a FWU metadata image.
 
-u-boot$ ./tools/mkfwumdata -i 1 -b 2 \
+u-boot$ ./tools/mkfwumdata -v 2 -i 1 -b 2 \
 	17e86d77-41f9-4fd7-87ec-a55df9842de5,10c36d7d-ca52-b843-b7b9-f9d6c501d108,5a66a702-99fd-4fef-a392-c26e261a2828,a8f868a1-6e5c-4757-878d-ce63375ef2c0 \
 	../devbox-fwu-mdata.img