linuxkpi: Add pci_iomap and pci_iounmap

Those function are use to map/unmap io region of a pci device.
Different resource can be mapped depending on the bar so use a
tailq to store them all.

Sponsored-by: The FreeBSD Foundation

Reviewed by: emaste, hselasky
Differential Revision: https://reviews.freebsd.org/D24696