arm64: qcom: Add support for Qualcomm MSM8916 SoC

Add support for Qualcomm MSM8916 SoC in arm64 Kconfig and defconfig.
Enable MSM8916 clock, pin control, and MSM serial driver utilized by
MSM8916 and Qualcomm SoCs in general.

Signed-off-by: Kumar Gala <galak@codeaurora.org>
Signed-off-by: Abhimanyu Kapur <abhimany@codeaurora.org>