Fix MISRA rule 8.4 Part 2

Rule 8.4: A compatible declaration shall be visible when
          an object or function with external linkage is defined

Fixed for:
	make DEBUG=1 PLAT=juno LOG_LEVEL=50 all

Change-Id: Ic8f611da734f356566e8208053296e6c62b54709
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>
diff --git a/include/plat/arm/css/common/css_pm.h b/include/plat/arm/css/common/css_pm.h
index 3842875..0f92e60 100644
--- a/include/plat/arm/css/common/css_pm.h
+++ b/include/plat/arm/css/common/css_pm.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2018, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -33,4 +33,10 @@
 void css_get_sys_suspend_power_state(psci_power_state_t *req_state);
 int css_node_hw_state(u_register_t mpidr, unsigned int power_level);
 
+/*
+ * This mapping array has to be exported by the platform. Each element at
+ * a given index maps that core to an SCMI power domain.
+ */
+extern const uint32_t plat_css_core_pos_to_scmi_dmn_id_map[];
+
 #endif /* __CSS_PM_H__ */