clk: si514: Migrate to clk_hw based OF and registration APIs

clk: si514: Migrate to clk_hw based OF and registration APIs

Now that we have clk_hw based provider APIs to register clks, we
can get rid of struct clk pointers while registering clks in
these drivers, allowing us to move closer to a clear split of
consumer and provider clk APIs.

Cc: Sebastian Hesselbarth <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Sören Brinkmann <[email protected]>
Cc: Mike Looijmans <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>