ARM: dts: qcom: msm8960: add clocks to the GCC device node

As we are converting this platform to use DT clock bindings, add clocks
and clock-names properties to the GCC device tree node.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Tested-by: David Heidelberg <david@ixit.cz> # tested on Nexus 7 (2013)
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20220623120418.250589-14-dmitry.baryshkov@linaro.org