clk: Provide dummy of_clk_get_from_provider() for compile-testing

When CONFIG_ON=n, dummies are provided for of_clk_get() and
of_clk_get_by_name(), but not for of_clk_get_from_provider().

Provide a dummy for the latter, to improve the ability to do
compile-testing.  This requires removing the existing dummy in the
Lantiq clock code.

Fixes: 766e6a4e ("clk: add DT clock binding support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Thomas Langer <thomas.langer@intel.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>