irqchip: Some Kconfig cleanup for C-SKY

Fixes to Kconfig help text:

- spell out "hardware"
- fix verb usage

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/d44baeee-cceb-7c02-7249-e6b4817f0847@infradead.org