hwrng: starfive - Enable compile testing

Enable compile testing for jh7110.  Also remove the dependency on
HW_RANDOM.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Jia Jie Ho <jiajie.ho@starfivetech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>