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/P2020DS.h b/include/configs/P2020DS.h
index 3fa38da..c69e092 100644
--- a/include/configs/P2020DS.h
+++ b/include/configs/P2020DS.h
@@ -719,7 +719,7 @@
 #define CONFIG_IPADDR		192.168.1.254
 
 #define CONFIG_HOSTNAME		unknown
-#define CONFIG_ROOTPATH		/opt/nfsroot
+#define CONFIG_ROOTPATH		"/opt/nfsroot"
 #define CONFIG_BOOTFILE		uImage
 #define CONFIG_UBOOTPATH	u-boot.bin	/* U-Boot image on TFTP server */