clk: socfpga: stratix10: simplify parameter passing

Just pass the clock pointer structure to the various register functions.

Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
Link: https://lkml.kernel.org/r/20200114160726.19771-2-dinguyen@kernel.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>