video: bridge: tc358768: remove need in clock name

Bridge uses only one clock and enforcing name to be set may
cause issues in the future.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
diff --git a/drivers/video/bridge/tc358768.c b/drivers/video/bridge/tc358768.c
index 6f1b057..358004f 100644
--- a/drivers/video/bridge/tc358768.c
+++ b/drivers/video/bridge/tc358768.c
@@ -951,7 +951,7 @@
 	}
 
 	/* get clk */
-	priv->refclk = devm_clk_get(dev, "refclk");
+	priv->refclk = devm_clk_get(dev, NULL);
 	if (IS_ERR(priv->refclk)) {
 		log_debug("%s: Could not get refclk: %ld\n",
 			  __func__, PTR_ERR(priv->refclk));