lib/crypto: aes: Drop 'volatile' from aes_sbox and aes_inv_sbox

lib/crypto: aes: Drop 'volatile' from aes_sbox and aes_inv_sbox

The volatile keyword is no longer necessary or useful on aes_sbox and
aes_inv_sbox, since the table prefetching is now done using a helper
function that casts to volatile itself and also includes an optimization
barrier.  Since it prevents some compiler optimizations, remove it.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-36-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>