We're removing struct clk from the clk provider API, so switch
this code to using the clk_hw based provider APIs.

Cc: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>