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/mpc7448hpc2.h b/include/configs/mpc7448hpc2.h
index 700dcda..61d758e 100644
--- a/include/configs/mpc7448hpc2.h
+++ b/include/configs/mpc7448hpc2.h
@@ -129,7 +129,7 @@
 #define CONFIG_TSI108_ETH_NUM_PORTS	2
 
 
-#define CONFIG_BOOTFILE		zImage.initrd.elf
+#define CONFIG_BOOTFILE		"zImage.initrd.elf"
 #define CONFIG_LOADADDR		0x400000
 
 /*-------------------------------------------------------------------------- */