crypto: qat - remove unused function

Remove unused function qat_dh_get_params().
This is to fix the following warning when compiling the driver with
CC=clang W=1

    drivers/crypto/qat/qat_common/qat_asym_algs.c:207:34: warning: unused function 'qat_dh_get_params' [-Wunused-function]
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reviewed-by: Fiona Trahe <fiona.trahe@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/qat/qat_common/qat_asym_algs.c

@@ -204,11 +204,6 @@ static unsigned long qat_dh_fn_id(unsigned int len, bool g2)
 	};
 }
 
-static inline struct qat_dh_ctx *qat_dh_get_params(struct crypto_kpp *tfm)
-{
-	return kpp_tfm_ctx(tfm);
-}
-
 static int qat_dh_compute_value(struct kpp_request *req)
 {
 	struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);