target/arm: Always clear exclusive monitor on reset

target/arm: Always clear exclusive monitor on reset

There's no particular reason why the exclusive monitor should
be only cleared on reset in system emulation mode. It doesn't
hurt if it isn't cleared in user mode, but we might as well
reduce the amount of code we have that's inside an ifdef.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210914120725.24992-3-peter.maydell@linaro.org