PCI: acpiphp: Remove unused acpiphp_callback typedef

Remove the 'acpiphp_callback' typedef as it is not used.

Link: https://lore.kernel.org/r/1613443120-4279-1-git-send-email-chen45464546@163.com


Signed-off-by: Chen Lin <chen.lin5@zte.com.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Krzysztof Wilczyński <kw@linux.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>