[ARM] S3C64XX: sparse warnings in arch/arm/plat-s3c64xx/irq.c

Fix the following sparse warnings in arch/arm/plat-s3c64xx/irq.c

arch/arm/plat-s3c64xx/irq.c:210:23: warning: incorrect type in initializer (different address spaces)
arch/arm/plat-s3c64xx/irq.c:210:23:    expected void *reg_base
arch/arm/plat-s3c64xx/irq.c:210:23:    got void [noderef] <asn:2>*regs
arch/arm/plat-s3c64xx/irq.c:215:2: warning: incorrect type in argument 1 (different address spaces)
arch/arm/plat-s3c64xx/irq.c:215:2:    expected void const volatile [noderef] <asn:2>*<noident>
arch/arm/plat-s3c64xx/irq.c:215:2:    got void *

Signed-off-by: Ben Dooks <ben-linux@fluff.org>