common: cosmetic: CONFIG_BOOTFILE checkpatch compliance

Remove MK_STR from places that consume CONFIG_BOOTFILE 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/idmr.h b/include/configs/idmr.h
index 3fe8f70..50dd918 100644
--- a/include/configs/idmr.h
+++ b/include/configs/idmr.h
@@ -56,7 +56,7 @@
 #define CONFIG_GATEWAYIP	192.168.1.1
 #define CONFIG_NETMASK		255.255.0.0
 #define CONFIG_HOSTNAME		idmr
-#define CONFIG_BOOTFILE		/tftpboot/idmr/uImage
+#define CONFIG_BOOTFILE		"/tftpboot/idmr/uImage"
 #define CONFIG_PREBOOT		"echo;echo Type \\\"run flash_nfs\\\" to mount root " \
 				"filesystem over NFS; echo"