Add RX lane margining settings for 16.0 GT/s (GEN 4) data rate.

These settings improve link stability while operating at high date
rates and helps to improve signal quality.

Link: https://lore.kernel.org/linux-pci/20240911-pci-qcom-gen4-stability-v7-4-743f5c1fd027@linaro.orgTested-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Shashank Babu Chinta Venkata <quic_schintav@quicinc.com>
[mani: dropped the code refactoring and minor changes]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>