radeonsi: don't always update shader coherency draw call counter
The bug report has a sequence that looks like this:
- set tex as framebuffer
- dispatch a compute shader that doesn't use tex
- dispatch a compute shader that uses it
Since we were updating the counters at step 2, step 3 failed to realize that calling si_make_CB_shader_coherent was needed.
While at it, this commit splits the draw call tracking counter in 2: one for CB, one for DB.
Closes: #11638 (closed) Cc: mesa-stable