PCI: imx6: Move imx6_pcie_clk_disable() earlier

Move imx6_pcie_clk_disable() earlier to be near other clock-related
functions.  No functional change intended.

[bhelgaas: reorder patch so pure moves are earlier]
Link: https://lore.kernel.org/r/1657783869-19194-5-git-send-email-hongxing.zhu@nxp.com


Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>