hwrng: stm32 - add reset during probe

[ Upstream commit 326ed382256475aa4b8b7eae8a2f60689fd25e78 ]

Avoid issue when probing the RNG without
reset if bad status has been detected previously

Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>