ARM: tegra: Convert PMC to a driver

This commit converts the PMC support code to a platform driver. Because
the boot process needs to call into this driver very early, also set up
a minimal environment via an early initcall.

Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/arch/arm/mach-tegra/platsmp.c b/arch/arm/mach-tegra/platsmp.c
index 0466a14..b450866 100644
--- a/arch/arm/mach-tegra/platsmp.c
+++ b/arch/arm/mach-tegra/platsmp.c
@@ -22,6 +22,7 @@
 #include <linux/smp.h>
 
 #include <soc/tegra/fuse.h>
+#include <soc/tegra/pmc.h>
 
 #include <asm/cacheflush.h>
 #include <asm/mach-types.h>
@@ -31,7 +32,6 @@
 #include "common.h"
 #include "flowctrl.h"
 #include "iomap.h"
-#include "pmc.h"
 #include "reset.h"
 
 static cpumask_t tegra_cpu_init_mask;