Clean up for the AMD-specific kernel launch info in the NextGen Plugins.
- Fixes a mistake introduced with the initial commit that added printing of an AMD-only property.
- Removes another AMD-only property (not clear on upstream status)
- Adds some more comment to what info is printed.
I would try to shorten this, like # for count, maybe SPGR/VPGR and then <N>/<M>, etc. But this is already better than what we had.