system/watchpoint: Move TCG specific code to accel/tcg/

Keep system/watchpoint.c accelerator-agnostic by moving
TCG specific code to accel/tcg/watchpoint.c. Update meson.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240111162032.43378-1-philmd@linaro.org>
3 files changed