cmd_date: make mk_date() static

Use static as this function is not used externally.

Signed-off-by: Alexander Feilke <alexander.feilke@ew.tq-group.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

cmd/date.c

@@ -16,7 +16,7 @@ static const char * const weekdays[] = {
 	"Sun", "Mon", "Tues", "Wednes", "Thurs", "Fri", "Satur",
 };
 
-int mk_date (const char *, struct rtc_time *);
+static int mk_date(const char *, struct rtc_time *);
 
 static struct rtc_time default_tm = { 0, 0, 0, 1, 1, 2000, 6, 0, 0 };
 
@@ -117,7 +117,7 @@ static int cnvrt2 (const char *str, int *valp)
  * Some basic checking for valid values is done, but this will not catch
  * all possible error conditions.
  */
-int mk_date (const char *datestr, struct rtc_time *tmp)
+static int mk_date(const char *datestr, struct rtc_time *tmp)
 {
 	int len, val;
 	char *ptr;