[CRYPTO] padlock: Get rid of padlock-generic.c

Merge padlock-generic.c into padlock-aes.c and compile
AES as a standalone module. We won't make a monolithic
padlock.ko with all supported algorithms, instead we'll
compile each driver into its own module.

Signed-off-by: Michal Ludvig <michal@logix.cz>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>