mailmap: update Li Yang's email address

Update the obsolete email address leoli@freescale.com and
leo@zh-kernel.org with leoyang.li@nxp.com.

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Li Yang <leoyang.li@nxp.com>
Signed-off-by: Weiwei Jia <harryxiyou@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>