Change Berserker Greaves to be lethality boots

Sorc boots are universally useful on AP champions because they give magic pen. Greaves are supposed to be the 'offensive' option for AD champions, but they only really work on AS based champions, mostly ADCs. Change the Greaves to be the same archetype as Sorc Boots so that AD champions can have a little more diversity. This would also make crit builds a little bit weaker.