Build: Include syscall stub file to resolve linker issue

GNU Arm compiler version greater equal than *11.3.Rel1* has a linker
issue that required system calls are missing, such as _read and _write.
Commit ea327cb5e ("Build: Add stub functions of system calls") added
syscalls_stubs.c file which has definitions of these functions. Include
them while building bl1_1, bl1_2, RSS CM and DM provisioning bundle.

Signed-off-by: Vijayenthiran Subramaniam <vijayenthiran.subramaniam@arm.com>
Change-Id: I65f3142164e347c67c4b7257f7b1ed78f1e7d719
4 files changed