bootm: Add support for passing arguments to elf app

This extends the bootm command to allow passing arguments to standalone
ELF applications.

Signed-off-by: Niu Zhihong <zone.niuzh@hotmail.com>
diff --git a/boot/bootm_os.c b/boot/bootm_os.c
index e9522cd..7e41e1f 100644
--- a/boot/bootm_os.c
+++ b/boot/bootm_os.c
@@ -402,7 +402,7 @@
 	if (flag != BOOTM_STATE_OS_GO)
 		return 0;
 
-	bootelf(bmi->images->ep, flags, 0, NULL);
+	bootelf(bmi->images->ep, flags, bmi->argc, bmi->argv);
 
 	return 1;
 }