net: phy: microchip: implement generic .handle_interrupt() callback

[ Upstream commit e01a3feb ]

In an attempt to actually support shared IRQs in phylib, we now move the
responsibility of triggering the phylib state machine or just returning
IRQ_NONE, based on the IRQ status register, to the PHY driver. Having
3 different IRQ handling callbacks (.handle_interrupt(),
.did_interrupt() and .ack_interrupt() ) is confusing so let the PHY
driver implement directly an IRQ handler like any other device driver.
Make this driver follow the new convention.

Cc: Nisar Sayed <Nisar.Sayed@microchip.com>
Cc: Yuiko Oshino <yuiko.oshino@microchip.com>
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 30a41ed3 ("net: phy: microchip: force IRQ polling mode for lan88xx")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>