MAINTAINERS: add mailing list for GPMI NAND driver

Add the imx@lists.linux.dev mailing list for the GPMI NAND driver.

Signed-off-by: Han Xu <han.xu@nxp.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20241011182603.346435-1-han.xu@nxp.com

Author: hanxu-nxp

MAINTAINERS

@@ -9028,6 +9028,7 @@ F:	drivers/net/ethernet/freescale/gianfar*
 
 FREESCALE GPMI NAND DRIVER
 M:	Han Xu <han.xu@nxp.com>
+L:	imx@lists.linux.dev
 L:	linux-mtd@lists.infradead.org
 S:	Maintained
 F:	drivers/mtd/nand/raw/gpmi-nand/*