irqchip/renesas-irqc: Get rid of IRQF_VALID

IRQF_VALID is not needed on ARM anymore, so get rid of it.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
Cc: jason@lakedaemon.net
Cc: geert+renesas@glider.be
Cc: horms@verge.net.au
Cc: Magnus Damm <magnus.damm@gmail.com>
Link: http://lkml.kernel.org/r/20150720100614.2552.86867.sendpatchset@little-apple
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>