Neovers N1: added support to update presence of External LLC

CPUECTLR_EL1.EXTLLC bit indicates the presense of internal or external
last level cache(LLC) in the system, the reset value is internal LLC.

To cater for the platforms(like N1SDP) which has external LLC present
introduce a new build option 'NEOVERSE_N1_EXTERNAL_LLC' which can be
enabled by platform port.

Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: Ibf475fcd6fd44401897a71600f4eafe989921363
4 files changed