On 6.6 kernel, clock-frequency flag name has been updated to
qcom,pcie-clock-frequency.
Update the clock-frequency dt flag name to qcom,pcie-clock-frequency.
Change-Id: I68c74d3b81ea65d30e7b8a2e8a432ad34d025077
Signed-off-by: Paras Sharma <quic_parass@quicinc.com>