soc: Tighten some soc driver dependencies

soc: Tighten some soc driver dependencies

The Qualcomm Snapdragon "SoC" driver cannot build without access to some
ARM64 specific functionality. Express that requirements in Kconfig as
well.

Reviewed-by: Casey Connolly <casey.connolly@linaro.org>
Signed-off-by: Tom Rini <trini@konsulko.com>