arm: meson: implement calls to secure monitor

Implement calls to secure monitor to read the MAC address from e-fuse.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
diff --git a/arch/arm/mach-meson/Makefile b/arch/arm/mach-meson/Makefile
index 44e3d63..bf49b8b 100644
--- a/arch/arm/mach-meson/Makefile
+++ b/arch/arm/mach-meson/Makefile
@@ -4,4 +4,4 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-obj-y += board.o
+obj-y += board.o sm.o