SPM: S-EL0 partitions support build for TC0

Add support for building Ivy for the TC0 platform. To do this
extend the Ivy build system to support building for multiple
platforms.

Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
Change-Id: I47298f00ba91f498826dd3ddd690309df01cc13e
12 files changed