CLK: HSDK: CGU: check if PLL is bypassed first

If PLL is bypassed the EN (enable) bit has no effect on
output clock.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Link: https://lkml.kernel.org/r/20200311134115.13257-2-Eugeniy.Paltsev@synopsys.com


Signed-off-by: Stephen Boyd <sboyd@kernel.org>