This will allow the q800-glue.h header to be included separately so that the
GLUE device can be referenced externally.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230621085353.113233-8-mark.cave-ayland@ilande.co.uk>
[lv: update comment]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>