etna_viv: Added package

User-space driver for the Vivante GCxxx series of embedded GPUs.

https://github.com/laanwj/etna_viv
libdrm: Bump version to 2.4.46

The latest mesa3d needs a higher version than we had before.
mesa3d-etna_viv: Added package

I created a separate package for this because it is significantly
different from package/x11r7/mesa3d. For one, it does not depend on X.