dummy_malloc: add calloc support

needed to use menu framework

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

common/dummy_malloc.c

@@ -24,3 +24,15 @@ void *realloc(void *ptr, size_t size)
 	BUG();
 }
 
+void *calloc(size_t n, size_t elem_size)
+{
+	size_t size = elem_size * n;
+	void *r = malloc(size);
+
+	if (!r)
+		return r;
+
+	memset(r, 0x0, size);
+
+	return r;
+}