clk: Provide !COMMON_CLK dummy for devm_clk_rate_exclusive_get()

To be able to compile drivers using devm_clk_rate_exclusive_get() also
on platforms without the common clk framework, add a dummy
implementation that does the same as clk_rate_exclusive_get() in that
case (i.e. nothing).

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202403270305.ydvX9xq1-lkp@intel.com/
Fixes: b0cde62e

 ("clk: Add a devm variant of clk_rate_exclusive_get()")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20240327073310.520950-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Stephen Boyd <sboyd@kernel.org>