Juno: Read primary CPU MPID from SCC GPR_1

This patch removes the PRIMARY_CPU definition hardcoded in the
Juno port. Instead, the primary CPU is obtained at runtime by
reading the SCC General Purpose Register 1 (GPR_1), whose value
is copied by the SCP into shared memory during the boot process.

Change-Id: I3981daa92eb7142250712274cf7f655b219837f5
diff --git a/plat/juno/juno_def.h b/plat/juno/juno_def.h
index b3099b7..1eae65d 100644
--- a/plat/juno/juno_def.h
+++ b/plat/juno/juno_def.h
@@ -34,8 +34,6 @@
 /* Special value used to verify platform parameters from BL2 to BL3-1 */
 #define JUNO_BL31_PLAT_PARAM_VAL	0x0f1e2d3c4b5a6978ULL
 
-#define JUNO_PRIMARY_CPU		0x100
-
 /*******************************************************************************
  * Juno memory map related constants
  ******************************************************************************/
@@ -194,4 +192,11 @@
 #define CCI400_SL_IFACE3_CLUSTER_IX	1
 #define CCI400_SL_IFACE4_CLUSTER_IX	0
 
+/*******************************************************************************
+ * SCP <=> AP boot configuration
+ ******************************************************************************/
+#define SCP_BOOT_CFG_ADDR	0x04000080
+#define PRIMARY_CPU_SHIFT	8
+#define PRIMARY_CPU_MASK	0xf
+
 #endif /* __JUNO_DEF_H__ */