net: dsa: felix: remove confusing/incorrect comment from felix_setup()

That comment was written prior to knowing that what I was actually
seeing was a manifestation of the bug fixed in commit b4024c9e


("felix: Fix initialization of ioremap resources").

There isn't any particular reason now why the hardware initialization is
done in felix_setup(), so just delete that comment to avoid spreading
misinformation.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>