staging: unisys: visorbus: renamed functions like my_device_* to match driver namespace

staging: unisys: visorbus: renamed functions like my_device_* to match driver namespace

Renamed functions
* my_device_create() to visorbus_device_create()
* my_device_changestate() to visorbus_device_changestate()
* my_device_destroy() to visorbus_device_destroy()

Signed-off-by: Sameer Wadgaonkar <sameer.wadgaonkar@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>