PCI: cpcihp: Remove unused struct cpci_hp_controller_ops.hardware_test

The 'hardware_test' field in struct cpci_hp_controller_ops is unused;
remove it to reduce resource consumption.

Link: https://lore.kernel.org/r/20241014131917.324667-1-trintaeoitogc@gmail.com


Signed-off-by: Guilherme Giacomo Simoes <trintaeoitogc@gmail.com>
[bhelgas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>