[media] exynos4-is: Leave FIMC clocks enabled when runtime PM is disabled

Driver should ensure a device can be also used normally when runtime
PM is disabled. So enable the FIMC clock in probe() in such situation.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>