MAINTAINERS: PCI: Add NXP PCI controller mailing list imx@lists.linux.dev

Add imx mailing list imx@lists.linux.dev for PCI controller of NXP chips
(Layerscape and iMX).

Link: https://lore.kernel.org/r/20240826202740.970015-1-Frank.Li@nxp.com


Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Richard Zhu <hongxing.zhu@nxp.com>