MAINTAINERS: Update Richard Zhu's email address

FSL emails may become invalid soon, so switch to the NXP one.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Richard Zhu <hongxing.zhu@nxp.com>

MAINTAINERS

@@ -9230,7 +9230,7 @@ S:	Maintained
 F:	drivers/pci/host/*layerscape*
 
 PCI DRIVER FOR IMX6
-M:	Richard Zhu <Richard.Zhu@freescale.com>
+M:	Richard Zhu <hongxing.zhu@nxp.com>
 M:	Lucas Stach <l.stach@pengutronix.de>
 L:	linux-pci@vger.kernel.org
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)