s390: provide default ioremap and iounmap declaration

Move the CONFIG_PCI device so that ioremap and iounmap are always
available. This looks safe as there's nothing PCI specific in the
implementation of these functions.

I have designs to use these functions in scatterlist.c where they'd likely
never be called without CONFIG_PCI set, but this is needed to compile
such changes.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>