crypto: loongson - Select CRYPTO_RNG

crypto: loongson - Select CRYPTO_RNG

This driver registers a rng_alg, so it requires CRYPTO_RNG.

Fixes: 766b2d724c8d ("crypto: loongson - add Loongson RNG driver support")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202605201622.qWOiiZTV-lkp@intel.com/
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>