Merge branch 'remove-PHY_HAS_INTERRUPT'

Heiner Kallweit says:

====================
net: phy: replace PHY_HAS_INTERRUPT with a check for config_intr and ack_interrupt

Flag PHY_HAS_INTERRUPT is used only here for this small check. I think
using interrupts isn't possible if a driver defines neither
config_intr nor ack_interrupts callback. So we can replace checking
flag PHY_HAS_INTERRUPT with checking for these callbacks.
This allows to remove this flag from all driver configs.

v2:
- add helper for check in patch 1
- remove PHY_HAS_INTERRUPT from all drivers, not only Realtek
- remove flag PHY_HAS_INTERRUPT completely

v3:
- rebase patch 2
====================

Signed-off-by: David S. Miller <davem@davemloft.net>