Staging: hv: vmbus: Change the signature of vmbus_bus_init()

In preparation for making the vmbus driver an ACPI bus driver, change the
signature of vmbus_bus_init() to accept the irq value.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Abhishek Kane <v-abkane@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>