pinctrl: ocelot: Fix incorrect trigger of the interrupt.

pinctrl: ocelot: Fix incorrect trigger of the interrupt.

The interrupt controller can detect only link changes. So in case an
external device generated a level based interrupt, then the interrupt
controller detected correctly the first edge. But the problem was that
the interrupt controller was detecting also the edge when the interrupt
was cleared. So it would generate another interrupt.
The fix for this is to clear the second interrupt but still check the
interrupt line status.

Fixes: 6fd943db689e ("pinctrl: ocelot: Fix interrupt controller")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Tested-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20221018070959.1322606-1-horatiu.vultur@microchip.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>