Bug 1670839 - Only build sha1-armv8.c code when USE_HW_SHA1 is define…

…d. r=kjacobs

This matches what is done in sha256-armv8.c, and avoids inconsistency with
sha1-fast.c, which will define the same functions in the case USE_HW_SHA1
is not defined.

Differential Revision: https://phabricator.services.mozilla.com/D93303

--HG--
extra : moz-landing-system : lando

lib/freebl/sha1-armv8.c

@@ -2,7 +2,11 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#ifdef __ARM_FEATURE_CRYPTO
+#ifdef USE_HW_SHA1
+
+#ifndef __ARM_FEATURE_CRYPTO
+#error "Compiler option is invalid"
+#endif
 
 #ifdef FREEBL_NO_DEPEND
 #include "stubs.h"
@@ -257,4 +261,4 @@ shaCompress(SHA_HW_t *X, const PRUint32 *inbuf)
     XH(4) = e;
 }
 
-#endif /* __ARM_FEATURE_CRYPTO */
+#endif /* USE_HW_SHA1 */