clk: qcom: gcc-mdm9615: drop the cxo clock

clk: qcom: gcc-mdm9615: drop the cxo clock

The gcc and lcc devices have been switched to the DT-defined cxo_board
clock. Now we can drop the manually defined cxo clock.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230512211727.3445575-9-dmitry.baryshkov@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>