feat(rdn2): enable Neoverse N2 CPU error handling support

Defines N2 CPU RAS error for RD-N2 platform variants. Enables N2 CPU
error handling on RD-N2 platform variants.

Signed-off-by: Omkar Anand Kulkarni <omkar.kulkarni@arm.com>
Change-Id: If9378064c41e0d14e6c789c71f8def594f89e220
2 files changed