ARM platforms: Provide SDEI entry point validation

Provide a strong definition for plat_sdei_validate_sdei_entrypoint()
which translates client address to Physical Address, and then validating
the address to be present in DRAM.

Change-Id: Ib93eb66b413d638aa5524d1b3de36aa16d38ea11
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/include/lib/aarch64/arch.h b/include/lib/aarch64/arch.h
index 16d12a3..cb7dab7 100644
--- a/include/lib/aarch64/arch.h
+++ b/include/lib/aarch64/arch.h
@@ -598,4 +598,10 @@
 
 #define MAKE_MAIR_NORMAL_MEMORY(inner, outer)	((inner) | ((outer) << MAIR_NORM_OUTER_SHIFT))
 
+/* PAR_EL1 fields */
+#define PAR_F_SHIFT	0
+#define PAR_F_MASK	1
+#define PAR_ADDR_SHIFT	12
+#define PAR_ADDR_MASK	(BIT(40) - 1) /* 40-bits-wide page address */
+
 #endif /* __ARCH_H__ */