Staging: hv: delete vmbus_hid_protocol.h

The .h file is not needed as only one .c file uses it, so just move
it into that file.

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