staging: unisys: visorbus: Rename what vmcallinterface.h #define

Renames __IOMONINTF_H__ to __VMCALLINTERFACE_H__, which more closely
reflects the naming conventions of the code.

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