mailmap: Add WeiXiong Liao

WeiXiong Liao noted to me offlist that his preference for email address
had changed and that he'd like it updated in the mailmap so people
discussing pstore/blk would be able to reach him.

Cc: WeiXiong Liao <gmpy.liaowx@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

.mailmap

@@ -319,6 +319,7 @@ Vivien Didelot <vivien.didelot@gmail.com> <vivien.didelot@savoirfairelinux.com>
 Vlad Dogaru <ddvlad@gmail.com> <vlad.dogaru@intel.com>
 Vladimir Davydov <vdavydov.dev@gmail.com> <vdavydov@parallels.com>
 Vladimir Davydov <vdavydov.dev@gmail.com> <vdavydov@virtuozzo.com>
+WeiXiong Liao <gmpy.liaowx@gmail.com> <liaoweixiong@allwinnertech.com>
 Will Deacon <will@kernel.org> <will.deacon@arm.com>
 Wolfram Sang <wsa@kernel.org> <w.sang@pengutronix.de>
 Wolfram Sang <wsa@kernel.org> <wsa@the-dreams.de>