tegra: tegra124: Add a PMC syscon driver

The PMC can be modelled as a syscon peripheral. Add a driver for this
so that it can be accessed by drivers when needed. Enable it for tegra124
boards.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Tested-on: Beaver, Jetson-TK1
Tested-by: Stephen Warren <swarren@nvidia.com>
diff --git a/arch/arm/mach-tegra/tegra124/Makefile b/arch/arm/mach-tegra/tegra124/Makefile
index c00de61..d275daf 100644
--- a/arch/arm/mach-tegra/tegra124/Makefile
+++ b/arch/arm/mach-tegra/tegra124/Makefile
@@ -10,6 +10,7 @@
 obj-y	+= clock.o
 obj-y	+= funcmux.o
 obj-y	+= pinmux.o
+obj-y	+= pmc.o
 obj-y	+= xusb-padctl.o
 obj-y	+= ../xusb-padctl-common.o