radeonsi: do only 1 big CE dump at end of IBs and one reload in the preamble

radeonsi: do only 1 big CE dump at end of IBs and one reload in the preamble

A later commit will only upload descriptors used by shaders, so we won't do
full dumps anymore, so the only way to have a complete mirror of CE RAM
in memory is to do a separate dump after the last draw call.

Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>