clk: qcom: add common gdsc_gx_do_nothing_enable for gpucc drivers

All gpucc drivers need this, so move it to common code instead of
duplicating it in every gpucc driver.

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20200709135251.643-10-jonathan@marek.ca


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