soc/samsung/exynos5250/dp-reg.c: Use __func__

Change-Id: I572ee7faaa4453d32852eea2b83b0b27c549abf2
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49566
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by:  Felix Singer <felixsinger@posteo.net>

src/soc/samsung/exynos5250/dp-reg.c

@@ -432,7 +432,7 @@ int s5p_dp_is_video_stream_on(struct s5p_dp_device *dp)
 	} while (!stopwatch_expired(&sw));
 
 	if (i != 4) {
-		printk(BIOS_DEBUG, "s5p_dp_is_video_stream_on timeout\n");
+		printk(BIOS_DEBUG, "%s timeout\n", __func__);
 		return -1;
 	}