gpio: kill off set_irq_flags usage

set_irq_flags is ARM specific with custom flags which have genirq
equivalents. Convert drivers to use the genirq interfaces directly, so we
can kill off set_irq_flags. The translation of flags is as follows:

IRQF_VALID -> !IRQ_NOREQUEST
IRQF_PROBE -> !IRQ_NOPROBE
IRQF_NOAUTOEN -> IRQ_NOAUTOEN

For IRQs managed by an irqdomain, the irqdomain core code handles clearing
and setting IRQ_NOREQUEST already, so there is no need to do this in
.map() functions and we can simply remove the set_irq_flags calls. Some
users also modify IRQ_NOPROBE and this has been maintained although it
is not clear that is really needed as most platforms don't use probing.
There appears to be a great deal of blind copy and paste of this code.

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-gpio@vger.kernel.org
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: linux-tegra@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-mcp23s08.c

@@ -507,11 +507,7 @@ static int mcp23s08_irq_setup(struct mcp23s08 *mcp)
 		irq_set_chip_data(irq, mcp);
 		irq_set_chip(irq, &mcp23s08_irq_chip);
 		irq_set_nested_thread(irq, true);
-#ifdef CONFIG_ARM
-		set_irq_flags(irq, IRQF_VALID);
-#else
 		irq_set_noprobe(irq);
-#endif
 	}
 	return 0;
 }