Build: Don't require ASM_NASM if !REQUIRE_SIMD The build system is supposed to fall back to a non-SIMD build if WITH_SIMD==1 but REQUIRE_SIMD==0. Based on: https://github.com/emlix/libjpeg-turbo/commit/972df912d08b755db3ca60d93b058a42e97a79eb Closes #384