Update description files for RK322X

[TonyXie06]

Update .travis.yml, MAINTAINERS.md and README.md for RK322X #1666

[jforissier]

Minor comment: you should probably drop the word "description" from ".travis.yml: Add Rockchip RK322X description".
Thanks for the updates and for adding yourself as a maintainer.

Acked-by: Jerome Forissier <jerome.forissier@linaro.org>

[TonyXie06]

Agreed, I will drop it.

jforissier, I discussed with my teammates and come to an advice: may I use a public email account as maintainer , just like "Rockchip rockchip-op-tee@rock-chips.com" ? Because there will be more Rockchip SoCs supported by me or my teammates in the future, many of us play different roles for porting and maintainance work.

[jforissier]

@TonyXie06 I think a "generic" maintainer address is fine. So, if it is more convenient for you please go ahead and update it.

[TonyXie06]

1. tags applied;
2. drop word "description" from ".travis.yml: Add Rockchip RK322X description";
3. update maintainer as "Rockchip op-tee@rock-chips.com".