net: phy: Stop with excessive soft reset

While consolidating the PHY reset in phy_init_hw() an unconditionaly
BMCR soft-reset I became quite trigger happy with those. This was later
on deactivated for the Generic PHY driver on the premise that a prior
software entity (e.g: bootloader) might have applied workarounds in
commit 0878fff1 ("net: phy: Do not perform software reset for
Generic PHY").

Since we have a hook to wire-up a soft_reset callback, just use that and
get rid of the call to genphy_soft_reset() entirely. This speeds up
initialization and link establishment for most PHYs out there that do
not require a reset.

Fixes: 87aa9f9c ("net: phy: consolidate PHY reset in phy_init_hw()")
Tested-by: Wang, Dongsheng <dongsheng.wang@hxt-semitech.com>
Tested-by: Chris Healy <cphealy@gmail.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>