Remove the hpc_ops struct from shpchp. This struct is unnecessary and no
other hotplug controller implements it. A similar thing has already been
done in pciehp with 82a9e79e ("PCI: pciehp: remove hpc_ops").

Link: https://lore.kernel.org/r/Zp-XXVW4hlcMASEc@archbtwSigned-off-by: ngn <ngn@ngn.tf>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>