sfc: QT2025C: Use hard reset only

At probe time, falcon_reset_hw() performs a hard reset of the PHY
along with Falcon.  There is no need to perform a soft reset later,
and any access to standard MDIO registers before the PHY firmware has
booted can interrupt the boot process, making the port unusable.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>