SPMD: add command line parameter to run SPM at S-EL2 or S-EL1 ...

Added SPMD_SPM_AT_SEL2 build command line parameter.
Set to 1 to run SPM at S-EL2.
Set to 0 to run SPM at S-EL1 (pre-v8.4 or S-EL2 is disabled).
Removed runtime EL from SPM core manifest.

Change-Id: Icb4f5ea4c800f266880db1d410d63fe27a1171c0
Signed-off-by: Artsem Artsemenka <artsem.artsemenka@arm.com>
Signed-off-by: Max Shvetsov <maksims.svecovs@arm.com>

SPMD: add support for an example SPM core manifest ...

This patch repurposes the TOS FW configuration file as the manifest for
the SPM core component which will reside at the secure EL adjacent to
EL3. The SPM dispatcher component will use the manifest to determine how
the core component must be initialised. Routines and data structure to
parse the manifest have also been added.

Signed-off-by: Achin Gupta <achin.gupta@arm.com>
Signed-off-by: Artsem Artsemenka <artsem.artsemenka@arm.com>
Change-Id: Id94f8ece43b4e05609f0a1d364708a912f6203cb