i2c: designware: suppress unneeded SDA hold time warnings

The hardware may not support SDA hold time configuration, but if it is
not set in the Device Tree either, there is no need to print a warning.

Reported-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Alexander Monakov <amonakov@ispras.ru>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-designware-master.c

@@ -163,7 +163,7 @@ static int i2c_dw_init_master(struct dw_i2c_dev *dev)
 		if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
 			dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT;
 		dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
-	} else {
+	} else if (dev->sda_hold_time) {
 		dev_warn(dev->dev,
 			"Hardware too old to adjust SDA hold time.\n");
 	}