target/mips: Implement CP0.Config7.WII bit support

target/mips: Implement CP0.Config7.WII bit support

Some pre-release 6 cores use CP0.Config7.WII bit to indicate that a
disabled interrupt should wake up a sleeping CPU.
Enable this bit by default for M14K(c) and P5600. There are potentially
other cores that support this feature, but I do not have a complete
list.

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@fungible.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230216051717.3911212-4-marcin.nowakowski@fungible.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>