PCI: rockchip: Set Target Link Speed to 5.0 GT/s before retraining

PCI: rockchip: Set Target Link Speed to 5.0 GT/s before retraining

Rockchip controllers can support up to 5.0 GT/s link speed. But the driver
doesn't set the Target Link Speed currently. This may cause failure in
retraining the link to 5.0 GT/s if supported by the endpoint. So set the
Target Link Speed to 5.0 GT/s in the Link Control and Status Register 2.

Fixes: e77f847df54c ("PCI: rockchip: Add Rockchip PCIe controller support")
Signed-off-by: Geraldo Nascimento <geraldogabriel@gmail.com>
[mani: fixed whitespace warning, commit message rewording, added fixes tag]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/0afa6bc47b7f50e2e81b0b47d51c66feb0fb565f.1751322015.git.geraldogabriel@gmail.com