PCI: imx6: Configure REF_USE_PAD before PHY reset for i.MX95

PCI: imx6: Configure REF_USE_PAD before PHY reset for i.MX95

According to the i.MX95 PCIe PHY Databook, the ref_use_pad signal in the
Common Block Signals section selects the reference clock source connected
to the PHY pads. Per the specification, any change to this input must be
followed by a PHY reset assertion to take effect.

Move the REF_USE_PAD configuration before the PHY reset toggle to comply
with the required initialization sequence.

Fixes: 47f54a902dcd ("PCI: imx6: Toggle the core reset for i.MX95 PCIe")
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
[mani: renamed the callback and helper to match the usecase]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260518072715.3166514-2-hongxing.zhu@nxp.com