dtsi: Update the nv-counter node in the device tree

Created a header file defining the id of the various nv-counters
used in the system.
Also, updated the device tree to add 'id' property for the trusted
and non-trusted nv-counters.

Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: Ia41a557f7e56ad4ed536aee11c7a59e078ae07c0
diff --git a/include/common/nv_cntr_ids.h b/include/common/nv_cntr_ids.h
new file mode 100644
index 0000000..a15c431
--- /dev/null
+++ b/include/common/nv_cntr_ids.h
@@ -0,0 +1,9 @@
+/*
+ * Copyright (c) 2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#define	TRUSTED_NV_CTR_ID	U(0)
+#define	NON_TRUSTED_NV_CTR_ID	U(1)
+#define	MAX_NV_CTR_IDS		U(2)