clk: samsung: Add enable/disable support for PLL35XX clocks

Some PLLs might be disabled by default after turning off and then on
a power domain which they belongs to.  To avoid configuring a disabled
PLL, add proper code for handling PLL enable/disable.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>