[ Upstream commit 9d83d299 ]

clk_prepare_enable() can fail so add a check for this and
return the error code if it fails.
Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>