Revert "phy: add support for a reset-gpio specification"

Commit da47b457 ("phy: add support for a reset-gpio specification")
causes the following xtensa qemu crash according to Guenter Roeck:

[    9.366256] libphy: ethoc-mdio: probed
[    9.367389]  (null): could not attach to PHY
[    9.368555]  (null): failed to probe MDIO bus
[    9.371540] Unable to handle kernel paging request at virtual address 0000001c
[    9.371540]  pc = d0320926, ra = 903209d1
[    9.375358] Oops: sig: 11 [#1]

This reverts commit da47b457.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>