common: cosmetic: CONFIG_ROOTPATH checkpatch compliance

Remove MK_STR from places that consume CONFIG_ROOTPATH to force all definitions to be string literals.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Cc: Joe Hershberger <joe.hershberger@gmail.com>
Cc: Wolfgang Denk <wd@denx.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/include/configs/grsim.h b/include/configs/grsim.h
index f868d96..df2b500 100644
--- a/include/configs/grsim.h
+++ b/include/configs/grsim.h
@@ -121,7 +121,7 @@
 #define CONFIG_GATEWAYIP 192.168.0.1
 #define CONFIG_SERVERIP 192.168.0.81
 #define CONFIG_IPADDR 192.168.0.80
-#define CONFIG_ROOTPATH /export/rootfs
+#define CONFIG_ROOTPATH "/export/rootfs"
 #define CONFIG_HOSTNAME  grxc3s1500
 #define CONFIG_BOOTFILE  /uImage