net: ravb: Do not shut down clock in start callback

net: ravb: Do not shut down clock in start callback

Do not stop the clock in the start callback in case of failure, keep
them running to also keep the PHY running. The failure could be ie.
PHY failing to negotiate link and if the clock get shut down, another
attempt at bringing the link up would fail. The clock right now are
started in probe function and stopped in remove function, which is
the correct behavior.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Cc: Joe Hershberger <joe.hershberger@ni.com>