crypto: aead - fix kernel-doc warnings in crypto/aead.h

Fix 21 occurrences of this kernel-doc warning in <crypto/aead.h>:

..//include/crypto/aead.h:149: warning: No description found for parameter 'base'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/include/crypto/aead.h b/include/crypto/aead.h
index 077cae1..84d13b1 100644
--- a/include/crypto/aead.h
+++ b/include/crypto/aead.h
@@ -128,6 +128,7 @@
  * @exit: Deinitialize the cryptographic transformation object. This is a
  *	  counterpart to @init, used to remove various changes set in
  *	  @init.
+ * @base: Definition of a generic crypto cipher algorithm.
  *
  * All fields except @ivsize is mandatory and must be filled.
  */