That would be the best.  However, it's not hard to do a
simple probing in the kernel until modprobe(8) gets this
feature.

Sounds like a big hack, and at least for aes / aes-x86_64 and
twofish it's not needed.  Just disable aes on x86.

The only problem is the select issue with wireless.

Unfortunately 

select CRYPTO_AES_X86_64 if X86_64
select CRYPTO_AES_I586 if X86_32
select CRYPTO_AES if !X86

produces warnings for unreferenced symbols :/
Perhaps it can be just removed for now.

quoted

Also if one implementation is always better than the other
then I see little reason to ever have both.

Well it's not that useful for an assembly implementation
that works on all instances of a given architecture.

I meant on x86. Sure for other architectures the C version is needed.

-Andi