gpio: fix locking open drain IRQ lines

gpio: fix locking open drain IRQ lines

[ Upstream commit e9bdf7e655b9ee81ee912fae1d59df48ce7311b6 ]

We provided the right semantics on open drain lines being
by definition output but incidentally the irq set up function
would only allow IRQs on lines that were "not output".

Fix the semantics to allow output open drain lines to be used
for IRQs.

Reported-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Tested-by: Hans Verkuil <hverkuil@xs4all.nl>
Cc: Russell King <linux@armlinux.org.uk>
Cc: stable@vger.kernel.org # v5.3+
Link: https://lore.kernel.org/r/20200527140758.162280-1-linus.walleij@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>