clk: mvebu: migrate CP110 system controller to clk_hw API and registration

Now that we have clk_hw based provider APIs to register clks, we
can get rid of struct clk pointers while registering clks in Armada
CP110 system controller driver. This commit introduces new
API and registration for all clocks in CP110 HW blocks.

Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>