[S390] irqflags: add missing types.h include

Add missing types.h include. Otherwise would cause build breakages on
hw breakpoint support, because of undefined BITS_PER_LONG.
Also fix up the copyright line and remove the superfluous __KERNEL__
ifdef.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>