feat(board/rdn2): enable base element RAM RAS support on RD-N2 platform

To enable firmware first support for base element RAMs on RD-N2 platform
this patch adds following support
- Includes SDEI header to enable SDEI feature on RD-N2 platform.
- Add TZC configuration for CPER memory region for RD-N2 platform
  variants. This region is marked for non-secure access as OSPM and
  firmware need to access this region.
- Defines all base element RAM errors for RD-N2 platform variants.
- Defines a platform RAS event map and respective RAS config data
  structure.

Signed-off-by: Omkar Anand Kulkarni <omkar.kulkarni@arm.com>
Change-Id: Ideaed598f4924f3b9836d4d7e9ef76b9b7580b48
diff --git a/plat/arm/board/rdn2/include/platform_def.h b/plat/arm/board/rdn2/include/platform_def.h
index 8e63de5..ff1a437 100644
--- a/plat/arm/board/rdn2/include/platform_def.h
+++ b/plat/arm/board/rdn2/include/platform_def.h
@@ -8,7 +8,7 @@
 #define PLATFORM_DEF_H
 
 #include <lib/utils_def.h>
-
+#include <sgi_sdei.h>
 #include <sgi_soc_platform_def_v2.h>
 
 #if (CSS_SGI_PLATFORM_VARIANT == 1)