ARM: crypto: comment out gcc warning that breaks clang builds

The gcc build warning prevents all clang-built kernels from working
properly, so comment it out to fix the build.

This is a -stable kernel only patch for now, it will be resolved
differently in mainline releases in the future.

Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: "Justin M. Forbes" <jforbes@fedoraproject.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>