fastboot: implement Kconfig

implement Kconfig for the 'fastboot' feature set

Signed-off-by: Steve Rae <steve.rae@raedomain.com>
diff --git a/cmd/Kconfig b/cmd/Kconfig
index e219246..d28da54 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -114,6 +114,8 @@
 
 endmenu
 
+source "cmd/fastboot/Kconfig"
+
 comment "Commands"
 
 menu "Info commands"