soc: qcom: ocmem_core: Add support for the new scm_call2 API

The scm library has added support for a new secure world
interface that is more aligned to the ARMv8 SMC calling
convention. Use the new API while maintaining backward
compatibility.

Change-Id: I2f56cde89673094b5b202fe3a4d3f95d80312402
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>