This is going to be needed by some drivers that handle more than one
device, like all other bus types do, so prepare for that in advance
before the user/kernel api is used.

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