PCI: Support Immediate Readiness on devices without PM capabilities

PCI: Support Immediate Readiness on devices without PM capabilities

Query support for Immediate Readiness irrespective of whether or not the
device supports PM capabilities, as nothing in the PCIe spec suggests that
Immediate Readiness is in any way dependent on PM functionality.

Fixes: d6112f8def51 ("PCI: Add support for Immediate Readiness")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: David Matlack <dmatlack@google.com>
Cc: Vipin Sharma <vipinsh@google.com>
Cc: Aaron Lewis <aaronlewis@google.com>
Link: https://patch.msgid.link/20250722155926.352248-1-seanjc@google.com