s390/kernel: add system calls for PCI memory access

Add the new __NR_s390_pci_mmio_write and __NR_s390_pci_mmio_read
system calls to allow user space applications to access device PCI I/O
memory pages on s390x platform.

[ Martin Schwidefsky: some code beautification ]

Signed-off-by: Alexey Ishchuk <aishchuk@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --cc arch/s390/include/uapi/asm/unistd.h
Simple merge

diff --cc arch/s390/kernel/compat_wrapper.c
Simple merge

diff --cc arch/s390/kernel/entry.h
Simple merge

diff --cc arch/s390/kernel/syscalls.S
Simple merge

diff --cc arch/s390/pci/Makefile
Simple merge

diff --cc arch/s390/pci/pci_mmio.c
Simple merge

diff --cc kernel/sys_ni.c
Simple merge