The idiomatic expression is steer clear of.
This ngram shows that "steer clear from" is never or rarely used, and I would write any examples off as mistakes.
If you do hear people say it, they may be mixing it up with similar expressions that use "from", such as:
- stay away from drugs
- keep clean from drugs
These mean pretty much the same thing as "steer clear of drugs".
The word "clear" has many uses and definitions, but the relevant definition here is:
Not touching; away from.
"the lorry was wedged in the ditch, one wheel clear of the ground"
Examples in other dictionaries all use "clear of" for this definition also.