cmd: add FDT setup for bootelf by flag

Added the ability to use FDT for ELF applications, required to run some
OS. To make FDT setup, you need to set the -d fdt_addr_r cmd option for
bootelf command. Enable by selecting CMD_ELF_FDT_SETUP.

Signed-off-by: Maxim Moskalets <Maxim.Moskalets@kaspersky.com>
diff --git a/cmd/Kconfig b/cmd/Kconfig
index bd5464a..61e280f 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -490,6 +490,17 @@
 	help
 	  Boot an ELF/vxWorks image from the memory.
 
+config CMD_ELF_FDT_SETUP
+	bool "Flattened Device Tree setup in bootelf cmd"
+	default n
+	depends on CMD_ELF
+	select LIB_LIBFDT
+	select LMB
+	help
+	  Do FDT setup in bootelf command optionally by param -d, which
+	  allows to bring additional system info (e.g. /memory node) to
+	  the Operating System or application.
+
 config CMD_FDT
 	bool "Flattened Device Tree utility commands"
 	default y