accel/tcg: Use vaddr for walk_memory_regions callback

accel/tcg: Use vaddr for walk_memory_regions callback

Use vaddr instead of target_ulong.  At the same time,
use int instead of unsigned long for flags, to match
page_set_flags().

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>