sparc64: Move AES driver over to a methods based implementation.

Instead of testing and branching off of the key size on every
encrypt/decrypt call, use method ops assigned at key set time.

Reverse the order of float registers used for decryption to make
future changes easier.

Align all assembler routines on a 32-byte boundary.
Signed-off-by: David S. Miller <davem@davemloft.net>