add a new public header for Mesa
Per #175 (closed), virgl_hw.h
is considered legacy and new things not virgl-specific should go into a new header.
This MR adds virglrenderer_hw.h
. The header consists of all definitions of opaque data consumed by virglrenderer.h
and is a companion header of virglrenderer.h
. It is a superset of virgl_hw.h
(and future venus_hw.h
).