tiny-printf: Add print_grouped_ull()

This function is used in the bootstage report which may be trigged in TPL
or TPL. Add a very basic implication of this function so that it builds.
There is no attempt to get the formatting right, since this would add too
much code size.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/lib/tiny-printf.c b/lib/tiny-printf.c
index 632b424..d46d206 100644
--- a/lib/tiny-printf.c
+++ b/lib/tiny-printf.c
@@ -389,3 +389,9 @@
 
 	return ret;
 }
+
+void print_grouped_ull(unsigned long long int_val, int digits)
+{
+	/* Don't try to print the upper 32-bits */
+	printf("%ld ", (ulong)int_val);
+}