ACPI / hotplug / PCI: Do not pass ACPI handle to hotplug_event()

Since hotplug_event() can get the ACPI handle needed for debug
printouts from its context argument, there's no need to pass the
handle to it.  Moreover, the second argument's type may be changed
to (struct acpiphp_context *), because that's what is always passed
to hotplug_event() as the second argument anyway.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>