radeon CS parser refactoring

[Dave Airlie]

> The following set of patches refactor the CS-parser logic
> in an effort to consolidate the code that is repeated across
> ASIC-specific files. All patches except #8 are function-neutral,
> that is they preserve the existing functionality of the driver.
> Patch #8 adds one extra check for WAIT_REG_MEM packet that I
> believe should be there.
>
> I have been running with these patches for about a month on several
> machines with Evergreen and NI GPUs without noticing any regressions.
> I also ran quick tests on all Radeon GPUs that I had around, which
> range from R300 through NI cards.

Did you run these with pre-kms userspace etc to make sure it doesn't
cause regressions there?

Dave.