memory: of_memory: Silence uninitialized variable warning

Presumably we never use the default: case statement which prints a
warning message.  But my static checker complains that if we do, we will
hit an uninitialized variable warning.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/memory/of_memory.c

@@ -109,7 +109,7 @@ const struct lpddr2_timings *of_get_ddr_timings(struct device_node *np_ddr,
 	struct lpddr2_timings	*timings = NULL;
 	u32			arr_sz = 0, i = 0;
 	struct device_node	*np_tim;
-	char			*tim_compat;
+	char			*tim_compat = NULL;
 
 	switch (device_type) {
 	case DDR_TYPE_LPDDR2_S2: