tools: Add mkfwumdata tool for FWU metadata image

Add 'mkfwumdata' tool to generate FWU metadata image for the meta-data
partition to be used in A/B Update imeplementation.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu@linaro.org>
diff --git a/tools/Kconfig b/tools/Kconfig
index 539708f..6e23f44 100644
--- a/tools/Kconfig
+++ b/tools/Kconfig
@@ -157,4 +157,13 @@
 	help
 	  Look Up Table Sequence
 
+config TOOLS_MKFWUMDATA
+	bool "Build mkfwumdata command"
+	default y if FWU_MULTI_BANK_UPDATE
+	help
+	  This command allows users to create a raw image of the FWU
+	  metadata for initial installation of the FWU multi bank
+	  update on the board. The installation method depends on
+	  the platform.
+
 endmenu