s390/cio: remove unused include linux/spinlock.h from cio.h

* The linux/spinlock.h header was included indirectly by the decompressor
and brought unnecessary build dependencies.
* Use proper includes in files which either directly or indirectly included
cio.h and were hidden until now by the included linux/spinlock.h, e.g.
linux/string.h for memcpy() or asm/page.h for PAGE_SIZE.

Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ipl: provide uapi header for list directed IPL

The IPL parameter block is used as an interface between Linux and
the machine to query and change the boot device and boot options.
To be able to create IPL parameter block in user space and pass it
as segment to kexec provide an uapi header with proper structure
definitions for the block.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/ipl: make ipl_info less confusing

The ipl_info union in struct ipl_parameter_block has the same name as
the struct ipl_info. This does not help while reading the code and the
union in struct ipl_parameter_block does not need to be named. Drop
the name from the union.

Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390: move ipl block and cmd line handling to early boot phase

To distinguish zfcpdump case and to be able to parse some of the kernel
command line arguments early (e.g. mem=) ipl block retrieval and command
line construction code is moved to the early boot phase.

"memory_end" is set up correctly respecting "mem=" and hsa_size in case
of the zfcpdump.

arch/s390/boot/string.c is introduced to provide string handling and
command line parsing functions to early boot phase code for the compressed
kernel image case.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>