net: ipa: kill ipa_version_supported()

The only place ipa_version_supported() is called is in the probe
function.  The version comes from the match data.  Rather than
checking the version validity separately, just consider anything
that has match data to be supported.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>