arm64: dts: qcom: msm8916: Add msm8916 A53 PLL DT node

Add a device tree node for the A53 PLL, which exists on msm8916
platforms.

Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>