Exynos: clock: Fix a bug in PLL lock check condition

The condition for testing of PLL getting locked was incorrect. Rectify
this error in this patch.

Reported-by: Alexei Fedorov <alexie.fedorov@arm.com>
Signed-off-by: Hatim Ali <hatim.rv@samsung.com>
Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>