crypto: x86/poly1305 - depend on generic library not generic shash

Remove the dependency on the generic Poly1305 driver. Instead, depend
on the generic library so that we only reuse code without pulling in
the generic skcipher implementation as well.

While at it, remove the logic that prefers the non-SIMD path for short
inputs - this is no longer necessary after recent FPU handling changes
on x86.

Since this removes the last remaining user of the routines exported
by the generic shash driver, unexport them and make them static.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

include/crypto/internal/poly1305.h

@@ -10,8 +10,6 @@
 #include <linux/types.h>
 #include <crypto/poly1305.h>
 
-struct shash_desc;
-
 /*
  * Poly1305 core functions.  These implement the ε-almost-∆-universal hash
  * function underlying the Poly1305 MAC, i.e. they don't add an encrypted nonce
@@ -28,13 +26,6 @@ void poly1305_core_blocks(struct poly1305_state *state,
 			  unsigned int nblocks, u32 hibit);
 void poly1305_core_emit(const struct poly1305_state *state, void *dst);
 
-/* Crypto API helper functions for the Poly1305 MAC */
-int crypto_poly1305_init(struct shash_desc *desc);
-
-int crypto_poly1305_update(struct shash_desc *desc,
-			   const u8 *src, unsigned int srclen);
-int crypto_poly1305_final(struct shash_desc *desc, u8 *dst);
-
 /*
  * Poly1305 requires a unique key for each tag, which implies that we can't set
  * it on the tfm that gets accessed by multiple users simultaneously. Instead we