MAINTAINERS: Remove Macpaul and add Rick as nds32 maintainer Macpaul have left Andestech for a while, and this mail... macpaul@andestech.com can not received mail... ...maintainer as Rick Chen <rick@andestech.com> Signed-off-by: Rick Chen <rick@andestech.com> Cc: KC Lin <kclin@andestech.com>