ipq40xx: dont panic on PSGMII calibration fail

Currently, in case that PSGMII calibration fails it will panic the kernel
which is not ideal and is preventing any debugging to be done.

So, since PGMII calibration failing only means that wired networking wont
work lets convet the panic() call to dev_error.

Link: https://github.com/openwrt/openwrt/pull/15542
Signed-off-by: Robert Marko <[email protected]>

target/linux/ipq40xx/patches-6.6/706-net-dsa-qca8k-add-IPQ4019-built-in-switch-support.patch

@@ -654,7 +654,7 @@ Signed-off-by: Robert Marko <[email protected]>
 +		}
 +	}
 +
-+	panic("PSGMII work is unstable !!! "
++	dev_err(priv->dev, "PSGMII work is unstable !!! "
 +		"Repeated recalibration attempts did not help(0x%x) !\n",
 +		test_result);
 +