mx35: Fix boot ROM hang in internal boot mode

If a watchdog reset occurs after booting in internal boot mode, the i.MX35
won't boot anymore. The boot ROM code seems to assume that some clocks are
turned on (they are after a power-on reset). This patch turns on the
necessary clocks.

Signed-off-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reported-by: John Ogness <jogness@linutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>