I am a little confused by the following statement:
"We have HBase tables where the data is in in Binary Avro format."
HBase stores data in HFiles and it's HBase's own format and not Avro. May be what you mean is you are exporting data from HBase into Avro and using Hive to read that data. If this is true, you can continue to do that as there are some advantages to this approach but if you want to keep data in HBase without moving it, then you can simply use Phoenix on top of HBase to read that data without moving it. In fact you can use Hive to read data in HBase. It's slow compared to Phoenix but it will do the job. May be that's what you are doing right now.
On the other hand, if you want to use Phoenix on top of HBase, you can read HBase tables from Phoenix using SQL. Again, you don't have to export data. Here is a link to quick start Phoenix.
The point is Avro doesn't come into play here and it's a little confusing why you are asking for Avro format. Between Phoenix and Drill, I would recommend using Phoenix because it's solely created for HBase and has better features and support compared to Drill.