Add support for video output switching. It appears no systems use HCI to

Add support for video output switching.  It appears no systems use HCI to
change the video output but use a separate device with a DSSX method
and a HID of "TOS6201" instead.  We use a pseudo-driver to get the handle
for this object and pass it to the acpi_toshiba driver.

This is untested but seems to match the Linux Toshiba driver.