This patch adds toggling phy reset if PHY is not attached. Otherwise,
some boards (e.g. R-Car H3 Salvator-XS) cannot link up correctly if
we do the following method:

 1) Kernel boots by using initramfs.
 --> No open the nic, so phy_device_register() and phy_probe()
     deasserts the reset.
 2) Kernel enters the suspend.
 --> So, keep the reset signal as deassert.
 --> On R-Car Salvator-XS board, unfortunately, the board power is
     turned off.
 3) Kernel returns from suspend.
 4) ifconfig eth0 up
 --> Then, since edge signal of the reset doesn't happen,
     it cannot link up.
 5) ifconfig eth0 down
 6) ifconfig eth0 up
 --> In this case, it can link up.
Reported-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>