The dependency on the async module was removed back in 0.6.0 (November
2014).
Whilst here, also merge the bb/inc and stop using PYTHON_PN, as we only
support Python 3.
(From OE-Core rev: 5fc09287ec8ca4332614eaa6b0dd5aabf10f6a31)
Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>