Hardware emulated models don't belong to the TCG MAINTAINERS
section. Move them to a new 'Overall MIPS Machines' section
in the 'MIPS Machines' group.

Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20211004092515.3819836-4-f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>