ARM: 6915/1: SAMSUNG: Depend on IRQ_GENERIC_CHIP

The generic chip infrastructure has had a Kconfig symbol added so we need
to select that for the kernel to link now we're using the generic IRQ
chip infrastructure.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>