staging: unisys: visorhba: remove unused (and broken) logic

The handling of CMD_NOTIFYGUEST_TYPE messages from the IO partition appears
to be only partially implemented, but fortunately it is never used in our
current environment.  This patch deletes the unused code.

Signed-off-by: Tim Sell <Timothy.Sell@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>