geos: Platform driver for Geos and Geos2 single-board computers.

Trivial platform driver for Traverse Technologies Geos and Geos2
single-board computers. Uses SMBIOS to identify platform.
Based on progressive revisions of the leds-net5501 driver that
was rewritten by Ed Wildgoose as a platform driver.

Supports GPIO-based LEDs (3) and 1 polled button which is
typically used for a soft reset.

Signed-off-by: Philip Prindeville <philipp@redfish-solutions.com>
Reviewed-by: Ed Wildgoose <ed@wildgooses.com>
Acked-by: Andres Salomon <dilinger@queued.net>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Garrett <mjg@redhat.com>