crypto: qcom-rng - Add missing dependency on hw_random

This should fix the undefined reference:

> /usr/bin/aarch64-alpine-linux-musl-ld: Unexpected GOT/PLT entries detected!
> /usr/bin/aarch64-alpine-linux-musl-ld: Unexpected run-time procedure linkages detected!
> /usr/bin/aarch64-alpine-linux-musl-ld: drivers/crypto/qcom-rng.o: in function `qcom_rng_probe':
> qcom-rng.c:(.text+0x130): undefined reference to `devm_hwrng_register'

Fixes: f29cd5bb ("crypto: qcom-rng - Add hw_random interface support")
Signed-off-by: André Apitzsch <git@apitzsch.eu>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>