net: phy: add genphy_handle_interrupt_no_ack()

It seems there are cases where the interrupts are handled by another
entity (ie an IRQ controller embedded inside the PHY) and do not need
any other interraction from phylib. For this kind of PHYs, like the
RTL8366RB, add the genphy_handle_interrupt_no_ack() function which just
triggers the link state machine.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>