Staging: hv: fix up driver registering mess

Individual drivers should never be touching the 'struct device' field,
so if that is a requirement to pass to the vmbus core, you know
something is wrong.

This patch fixes that all up, and resolves the problem where the module
reference counting was not happening properly for the individual drivers
as well.  Overall, it reduces the lines of code the individual drivers
have to have, which tells you that this is the correct thing to do.

Also, somehow the _GPL marking for the functions got removed on an older
patch.  As the name of the function was changing, properly change the
_GPL marking as well at the same time.

Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>