mips: cavium-octeon: Move octeon-crypto.h into asm directory

Since arch/mips/cavium-octeon/crypto/octeon-crypto.h is now needed
outside of its directory, move it to
arch/mips/include/asm/octeon/crypto.h so that it can be included as
<asm/octeon/crypto.h>.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250630160320.2888-10-ebiggers@kernel.org


Signed-off-by: Eric Biggers <ebiggers@kernel.org>