MAINTAINERS, .mailmap: Update my email address

Change from yorksun@freescale.com to york.sun@nxp.com.

Signed-off-by: York Sun <york.sun@nxp.com>
diff --git a/.mailmap b/.mailmap
index 2f32fe8..c7bb0ef 100644
--- a/.mailmap
+++ b/.mailmap
@@ -28,4 +28,5 @@
 TsiChung Liew <Tsi-Chung.Liew@freescale.com>
 Wolfgang Denk <wdenk>
 York Sun <yorksun@freescale.com>
+York Sun <york.sun@nxp.com>
 Ɓukasz Majewski <l.majewski@samsung.com>