After initializing the device, wait for it to report that the input
clock is present and the PLL has locked before declaring success.

Fixes: 3044a860 ("clk: Add Si5341/Si5340 driver")
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Link: https://lore.kernel.org/r/20210325192643.2190069-5-robert.hancock@calian.comSigned-off-by: Stephen Boyd <sboyd@kernel.org>