[r200] Lockups...

[Vladimir Dergachev]

I backed out the RadeonWaitForIdleMMIO() out of radeon_mergedfb.c.

Also, I am no longer able to observe the lockup on my hardware that I saw 
earlier, perhaps something else got fixed.

I am still curious to know what are the rules for accessing Radeon 
registers, perhaps, when I have more spare time, I'll write a small test 
problem to test what can cause them.

                                best

                                  Vladimir Dergachev