NTB: switchtec: Move structure definitions into a common header

NTB: switchtec: Move structure definitions into a common header

Create the switchtec.h header in include/linux with hardware defines
and the switchtec_dev structure. Both moved directly from switchtec.c.
This is a prep patch for creating an NTB driver for Switchtec.

Signed-off-by: Logan Gunthorpe <[email protected]>
Reviewed-by: Stephen Bates <[email protected]>
Reviewed-by: Kurt Schwemmer <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Acked-by: Bjorn Helgaas <[email protected]>
Signed-off-by: Jon Mason <[email protected]>