rsxx: Adding in debugfs entries.

Adding debugfs entries to help with debugging and testing and
testing code.

pci_regs:
       	This entry will spit out all of the data stored on the BAR.

stats:
       	This entry will display all of the driver stats for each
       	DMA channel.

cram:
	This will allow read/write ability to the CRAM address space
	on our adapter's CPU.

Signed-off-by: Philip J Kelleher <pjk1939@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>