staging: unisys: visorbus: remove #pragma directive

This patch removes the #pragma directive from visorchannel.h
and adds the __packed keyword to all structs to suppress structure
padding.

Signed-off-by: Jon Frisch <jon.frisch@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>