Add a new pending variable to ADBBusState which is a bitmask indicating which
ADB devices have data to send. Update the bitmask every time that an ADB
request is executed.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Tested-by: Finn Thain <fthain@telegraphics.com.au>
Acked-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200623204936.24064-13-mark.cave-ayland@ilande.co.uk>