cassini-[doc,config,distro]: Cassini 0.9.0 release
For the v0.9.0 release,:
- Sets DISTRO_VERSION to v0.9.0
- Pins all dependent layers
- Updates the documentation mentioning the v0.9.0 in the relevant sections
Changelog: other
Signed-off-by: Devaraj Ranganna devaraj.ranganna@arm.com