PCI: qcom: Use frequency and level based OPP lookup

PCI: qcom: Use frequency and level based OPP lookup

PCIe link configurations such as 8GT/s x2 and 16GT/s x1 may operate at the
same frequency, but differ in other characteristics like RPMh votes.  But
the existing OPP selection which is solely based on frequency (the 'opp-hz'
DT property) cannot distinguish between such cases.

Hence, use the newly introduced dev_pm_opp_find_key_exact() API to match
both frequency and level (the 'opp-level' property) when selecting an OPP,
here level indicates PCIe data rate.

To support older device trees where opp-level is not defined, check if
opp-level is present or not using dev_pm_opp_find_level_exact(). If
not present fallback to frequency only match.

Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
[mani: zero initialize dev_pm_opp_key struct]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
[bhelgaas: add 'opp-hz' and 'opp-level' in commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20251013-opp_pcie-v5-5-eb64db2b4bd3@oss.qualcomm.com