accel/tcg: Extract probe API out of 'exec/exec-all.h'

accel/tcg: Extract probe API out of 'exec/exec-all.h'

Declare probe methods in "accel/tcg/probe.h" to emphasize
they are specific to TCG accelerator.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Mark Cave-Ayland <mark.caveayland@nutanix.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20250424202412.91612-13-philmd@linaro.org>