radeonsi: use r600_common_context, r600_common_screen, r600_resource

Also r600_hw_context_priv.h and si_state_streamout.c are removed, because
they are no longer needed.

Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Tested-by: Tom Stellard <thomas.stellard@amd.com>
28 files changed