MAINTAINERS: Add git tree for KVM/mips

There is no git tree for KVM/mips in MAINTAINERS, it is not
convinent to rebase, add it.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
1 file changed