clk: add terminate callback to clk_ops

Add a terminate callback to the clk_ops to release the resources
claimed in .init()

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lkml.kernel.org/r/20190924123954.31561-4-jbrunet@baylibre.com


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