The WARN_ON() was only checking the first clock in the array, instead of
being executed for each clksrc clock being registered.

Since this is an array of clocks, WARN_ON() does not provide a lot of
useful information about the problem, so change to using printk(KERN_ERR)
to report the problem to the console.

As a note, we still try and register the clock even if these problems are
present just in case and to avoid changing the behaviour of the registration
process.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>