Various upgrades to umr including VM/MMHUB decoding

[Tom St Denis]

This patch series reflects a slew of changes that fell out of 
team meetings with mesa/kmd members over the last week.

We remove the "risky" option and the --print command since it's more
annoying than helpful.

We add the ability to specify the VMID in hex with --vram which
is handy with the last patch since you can specify which VM hub to use
in hex easier than in decimal.

The third patch includes various small cleanups found by static analysis
and code review.

The last patch includes two new features which were written at the same
time and were a bit tricky to separate (more effort than worth).  First,
we add the ability to halt waves when reading them which should help 
reading consistent data.  Next we add the ability to decode multimedia
IBs from the UVD/VCN rings.  Next we fix using the 'mmMC_VM_FB_LOCATION'
register which was traditionally zero on VI (and below) but now has
non-zero values which broke VM decoding.  Tested on Carrizo/Polaris/Raven.

Finally, the last patch adds the ability to specify a 'verbose' option
which prints out VM decoding information handy for debugging both umr and
the kmd.