staging: unisys: visorinput: Add default conditions to case statements

This commit adds a default condition to those case statements that do not
already have one. This is done to provide both a logical covering of all
conditions, as well as to maintain uniformity with the rest of the Unisys
driver set.

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