Read fix, Mifare Classic ACR 122 key loading optimizations

The Mifare Classic parts should be tested on the ACR 128 - it seems the key loading into volatile should be configurable on the number of slots + 'key structure' vs 'key number' offset. The current logic should work for ACR 122 and ACR 1222L, but both the old and the new logic seems incompatible with the spec on ACR 128.