crypto: lib/gf128mul - Remove some bbe deadcode

gf128mul_4k_bbe(), gf128mul_bbe() and gf128mul_init_4k_bbe()
are part of the library originally added in 2006 by
commit c494e070 ("[CRYPTO] lib: table driven multiplications in
GF(2^128)")

but have never been used.

Remove them.
(BBE is Big endian Byte/Big endian bits
Note the 64k table version is used and I've left that in)

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>