parisc: ccio-dma: Create private runway procfs root entry

Create an own procfs "runway" root entry for the CCIO driver.
No need to share it with the sba_iommu driver, as only one
of those busses can be active in one machine anyway.

Signed-off-by: Helge Deller <deller@gmx.de>
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 54725958 ("parisc: Move proc_mckinley_root and proc_runway_root to sba_iommu")
Cc: <stable@vger.kernel.org> # v6.5