s390: use generic asm-offsets.h

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

arch/s390/include/asm/Kbuild

+generic-y += asm-offsets.h
 generic-y += clkdev.h
 generic-y += dma-contiguous.h
 generic-y += export.h

arch/s390/include/asm/asm-offsets.h

-#include <generated/asm-offsets.h>