staging: unisys: visorbus: add __packed to structures in controlvmchannel.h

Added the __packed keyword to all structures in controlvmchannel.h
to ensure alignment and size in memory.

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