clk: Add clk_hw_*() APIs for use by clk providers

clk: Add clk_hw_*() APIs for use by clk providers

clk providers shouldn't need to use the consumer APIs (clk.h).
Add provider APIs to replace the __clk_*() APIs that take a
struct clk_hw as their first argument instead of a struct clk.

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