clk: s2mps11: Add missing of_node_put and of_clk_del_provider

Add of_clk_del_provider to remove previously registered clock provider.
Add of_node_put to decrement the ref count of clock nodes.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>