fs/fat: fix case for FAT shortnames

Noticed when comparing our output to linux.  There are some lcase bits
which control whether filename and/or extension should be downcase'd.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Łukasz Majewski <lukma@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>

include/fat.h

@@ -128,10 +128,14 @@ typedef struct volume_info
 	/* Boot sign comes last, 2 bytes */
 } volume_info;
 
+/* see dir_entry::lcase: */
+#define CASE_LOWER_BASE	8	/* base (name) is lower case */
+#define CASE_LOWER_EXT	16	/* extension is lower case */
+
 typedef struct dir_entry {
 	char	name[8],ext[3];	/* Name and extension */
 	__u8	attr;		/* Attribute bits */
-	__u8	lcase;		/* Case for base and extension */
+	__u8	lcase;		/* Case for name and ext (CASE_LOWER_x) */
 	__u8	ctime_ms;	/* Creation time, milliseconds */
 	__u16	ctime;		/* Creation time */
 	__u16	cdate;		/* Creation date */