SPM: Use separate source code for different models

Remove common API source 'spm_api.c', copy the common code to each
model's source files. This patch is to separate IPC and library
model source code before aligning with HAL data structure.

Change-Id: Id0d0f19f728cb27097465ae06b305831b8c26473
Signed-off-by: Mingyang Sun <Mingyang.Sun@arm.com>
6 files changed