staging: unisys: remove unused definitions from visorchipset.h

Delete visorchipset_get_switch_info() and visorchipset_get_externalport_info()
as these functions were declared but not defined, or used.

Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>