IB/ipath: chip initialisation code, and diag support

ipath_init_chip.c sets up an InfiniPath device for use.

ipath_diag.c permits userspace diagnostic tools to read and write a
chip's registers.  It is different in purpose from the mmap interfaces
to the /sys/bus/pci resource files.
Signed-off-by: Bryan O'Sullivan <bos@pathscale.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>