Handle this at the ADB bus level so that individual implementations do not need
to handle this themselves.
Finally add an assert() into adb_request() to prevent developers from accidentally
making an explicit ADB request without blocking autopoll.
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: <20200623204936.24064-21-mark.cave-ayland@ilande.co.uk>