__phy_hwtstamp_set function were calling the phy_mii_ioctl function
which will then use the ifreq pointer to call the hwtstamp callback.
Now that ifreq has been removed from the hwstamp callback parameters
it seems more logical to not go through the phy_mii_ioctl function and pass
directly kernel_hwtstamp_config parameter to the hwtstamp callback.

Lets do the same for __phy_hwtstamp_get function and return directly
EOPNOTSUPP as SIOCGHWTSTAMP is not supported for now for the PHYs.
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>