crypto: ccm - switch to separate cbcmac driver

Update the generic CCM driver to defer CBC-MAC processing to a
dedicated CBC-MAC ahash transform rather than open coding this
transform (and much of the associated scatterwalk plumbing) in
the CCM driver itself.

This cleans up the code considerably, but more importantly, it allows
the use of alternative CBC-MAC implementations that don't suffer from
performance degradation due to significant setup time (e.g., the NEON
based AES code needs to enable/disable the NEON, and load the S-box
into 16 SIMD registers, which cannot be amortized over the entire input
when using the cipher interface)
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/Kconfig

@@ -263,6 +263,7 @@ comment "Authenticated Encryption with Associated Data"
 config CRYPTO_CCM
 	tristate "CCM support"
 	select CRYPTO_CTR
+	select CRYPTO_HASH
 	select CRYPTO_AEAD
 	help
 	  Support for Counter with CBC MAC. Required for IPsec.