ARM: dts: qcom: msm8226: add clocks and clock-names to GCC node

Add the XO and Sleep Clock sources to the GCC node on MSM8226.

Signed-off-by: Rayyan Ansari <rayyan@ansari.sh>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230121192540.9177-3-rayyan@ansari.sh