crypto: caam - Provide the name of the function and provide missing descriptions

Fixes the following W=1 kernel build warning(s):

drivers/crypto/caam/caampkc.c:199: warning: expecting prototype for from a given scatterlist(). Prototype was for caam_rsa_count_leading_zeros() instead
drivers/crypto/caam/caamalg_qi2.c:87: warning: Function parameter or member 'xts_key_fallback' not described in 'caam_ctx'
drivers/crypto/caam/caamalg_qi2.c:87: warning: Function parameter or member 'fallback' not described in 'caam_ctx'

Cc: "Horia Geantă" <[e-mail]>
Cc: Aymen Sghaier <[e-mail]>
Cc: Herbert Xu <[e-mail]>
Cc: "David S. Miller" <[e-mail]>
Cc: [e-mail]
Signed-off-by: Lee Jones <[e-mail]>
Reviewed-by: Horia Geantă <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

drivers/crypto/caam/caamalg_qi2.c

···
  * @adata: authentication algorithm details
  * @cdata: encryption algorithm details
  * @authsize: authentication tag (a.k.a. ICV / MAC) size
+ * @xts_key_fallback: true if fallback tfm needs to be used due
+ *		      to unsupported xts key lengths
+ * @fallback: xts fallback tfm
  */
 struct caam_ctx {
 	struct caam_flc flc[NUM_OP];

drivers/crypto/caam/caampkc.c

···
 }
 
 /**
- * Count leading zeros, need it to strip, from a given scatterlist
+ * caam_rsa_count_leading_zeros - Count leading zeros, need it to strip,
+ *                                from a given scatterlist
  *
  * @sgl   : scatterlist to count zeros from
  * @nbytes: number of zeros, in bytes, to strip