[PATCH] ioc4: Core driver rewrite

This series of patches reworks the configuration and internal structure
of the SGI IOC4 I/O controller device drivers.

These changes are motivated by several factors:

- The IOC4 chip PCI resources are of mixed use between functions (i.e.
  multiple functions are handled in the same address range, sometimes
  within the same register), muddling resource ownership and initialization
  issues.  Centralizing this ownership in a core driver is desirable.

- The IOC4 chip implements multiple functions (serial, IDE, others not
  yet implemented in the mainline kernel) but is not a multifunction
  PCI device.  In order to properly handle device addition and removal
  as well as module insertion and deletion, an intermediary IOC4-specific
  driver layer is needed to handle these operations cleanly.

- All IOC4 drivers are currently enabled by a single CONFIG value.  As
  not all systems need all IOC4 functions, it is desireable to enable
  these drivers independently.

- The cur...