accel/tcg: Rename target-specific 'internal.h' -> 'internal-target.h'

accel/tcg: Rename target-specific 'internal.h' -> 'internal-target.h'

accel/tcg/internal.h contains target specific declarations.
Unit files including it become "target tainted": they can not
be compiled as target agnostic. Rename using the '-target'
suffix to make this explicit.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Anton Johansson <anjo@rev.ng>
Message-Id: <20230914185718.76241-9-philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>