crypto: Kconfig - add submenus

Convert each comment section into a submenu:
  Cryptographic API
    Crypto core or helper
    Public-key cryptography
    Block ciphers
    Length-preserving ciphers and modes
    AEAD (authenticated encryption with associated data) ciphers
    Hashes, digests, and MACs
    CRCs (cyclic redundancy checks)
    Compression
    Random number generation
    Userspace interface

That helps find entries (e.g., searching for a name like SHA512 doesn't
just report the location is Main menu -> Cryptography API, leaving you
to wade through 153 entries; it points you to the Digests page).

Move entries so they fall into the correct submenus and are
better sorted.

Suggested-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Robert Elliott <elliott@hpe.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>