timbgpio: fix build

Use of get_irq_chip_data() et al.  requires including linux/irq.h

Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Richard Röjfors <richard.rojfors@pelagicore.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>