MAINTAINERS: imx: Change Fabio's email address

I prefer to use my personal email address for kernel related work.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

MAINTAINERS

@@ -1531,7 +1531,7 @@ ARM/FREESCALE IMX / MXC ARM ARCHITECTURE
 M:	Shawn Guo <shawnguo@kernel.org>
 M:	Sascha Hauer <s.hauer@pengutronix.de>
 R:	Pengutronix Kernel Team <kernel@pengutronix.de>
-R:	Fabio Estevam <fabio.estevam@nxp.com>
+R:	Fabio Estevam <festevam@gmail.com>
 R:	NXP Linux Team <linux-imx@nxp.com>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained