PCI: imx6: Fix reference clock source selection for i.MX95

PCI: imx6: Fix reference clock source selection for i.MX95

In the PCIe PHY init for the i.MX95, the reference clock source selection
uses a conditional instead of always passing the mask. This currently
breaks functionality if the internal refclk is used.

To fix this issue, always pass IMX95_PCIE_REF_USE_PAD as the mask and clear
bit if external refclk is not used. This essentially swaps the parameters.

Fixes: d8574ce57d76 ("PCI: imx6: Add external reference clock input mode support")
Signed-off-by: Franz Schnyder <franz.schnyder@toradex.com>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Richard Zhu <hongxing.zhu@nxp.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260325093118.684142-1-fra.schnyder@gmail.com