clk: Remove never used devm_of_clk_del_provider()

For the entire history of the devm_of_clk_del_provider) existence
(since 2017) it was never used. Remove it for good.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220623115719.52683-1-andriy.shevchenko@linux.intel.com


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