contrib/gitdm: add China Mobile to the domain map

We've had a number of contributions from this domain. Mao has
confirmed they are company contributions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Mao Zhongyi <maozhongyi@cmss.chinamobile.com>
Cc: Zhang Shengju <zhangshengju@cmss.chinamobile.com>

contrib/gitdm/domain-map

@@ -5,6 +5,7 @@
 #
 
 amd.com         AMD
+cmss.chinamobile.com China Mobile
 citrix.com      Citrix
 greensocs.com   GreenSocs
 fujitsu.com     Fujitsu