AMU: Implement support for aarch32

The `ENABLE_AMU` build option can be used to enable the
architecturally defined AMU counters.  At present, there is no support
for the auxiliary counter group.

Change-Id: Ifc7532ef836f83e629f2a146739ab61e75c4abc8
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>
diff --git a/bl32/sp_min/sp_min.mk b/bl32/sp_min/sp_min.mk
index 39588ce..56489a3 100644
--- a/bl32/sp_min/sp_min.mk
+++ b/bl32/sp_min/sp_min.mk
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -22,6 +22,10 @@
 BL32_SOURCES		+=	lib/pmf/pmf_main.c
 endif
 
+ifeq (${ENABLE_AMU}, 1)
+BL32_SOURCES		+=	lib/extensions/amu/aarch32/amu.c
+endif
+
 BL32_LINKERFILE	:=	bl32/sp_min/sp_min.ld.S
 
 # Include the platform-specific SP_MIN Makefile