refactor(qemu-sbsa): create accessor functions for platform info

Creating accessor functions to access information held by struct
qemu_platform_info. That way the code that is relevant to fetching
information from the device tree can be taken out of sbsa_sip_svc.c and
placed in a file where other client can use the information it provides.

No change in functionality.

Change-Id: I989952ee6d15e1436549002dd7c7767c745ea297
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2 files changed