buildtools-tarball: include nativesdk-python3-pyyaml
BitBake can optionally 'import yaml' if BB_LOGCONFIG specifies a yaml
file. This is a 3rd party module, so that this works out of the box
when buildtools is used -- either explicitly via buildtools-tarball or
implicitly via eSDK -- we can add pyyaml to the buildtools.
Signed-off-by: Ross Burton <ross.burton@arm.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>