MIPS CPS and GIC models are unrelated to the TCG frontend.
Move them as new sections under the 'Devices' group.

Cc: Paul Burton <paulburton@kernel.org>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211027041416.1237433-3-f4bug@amsat.org>