Hexagon: Provide basic implementation and/or stubs for I/O routines.
Filled in the ins/outs; leaving them in for now.
Change _IO_BASE and IO_SPACE_LIMIT for safety.
I have compiled this with sparse and it builds; I've also picked over
various files related to the HAS_IOPORT_MAP from arm-soc.git and
tried them out, and they work, so I guess we'll just wait until
they're merged.
Signed-off-by: Richard Kuo <rkuo@codeaurora.org> Signed-off-by: Linas Vepstas <linas@codeaurora.org>