armv8: cavium: Add an implementation of ATF calling functions

This commit adds functions issuing calls to the product-specific ATF
services

Signed-off-by: Sergey Temerkhanov <s.temerkhanov@gmail.com>
Signed-off-by: Radha Mohan Chintakuntla <rchintakuntla@cavium.com>
diff --git a/include/configs/thunderx_88xx.h b/include/configs/thunderx_88xx.h
index 9bd26dc..cece4dd 100644
--- a/include/configs/thunderx_88xx.h
+++ b/include/configs/thunderx_88xx.h
@@ -26,6 +26,8 @@
 
 #define CONFIG_SYS_FULL_VA
 
+#define CONFIG_SYS_LOWMEM_BASE		MEM_BASE
+
 #define CONFIG_SYS_MEM_MAP		{{0x000000000000UL, 0x40000000000UL, \
 					  PTL2_MEMTYPE(MT_NORMAL) |	     \
 					  PTL2_BLOCK_NON_SHARE},	     \