remove enum docs

These docs repeat the possible values for these enums at
the time they were written ad nauseum.  They're not kept
up to date.

This is the result of searching for "one of" and deleting most.
I did keep one set of docs where some enum values were permitted
on some platforms and others on others.  And I kept docs for args
that didn't take enums but only accepted a particular range, like
[0,8] for matrix value indices or 0-4 for pixel size shifts.

Change-Id: Ib21ec54ebbc4abe456e9b3f436f3823d7da9097d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/270107
Auto-Submit: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Mike Reed <reed@google.com>
13 files changed