common: Move reset_cpu() to the CPU header

Move this function out of common.h and into a relevant header file.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/mach-tegra/pmc.c b/arch/arm/mach-tegra/pmc.c
index afd3c54..68a2112 100644
--- a/arch/arm/mach-tegra/pmc.c
+++ b/arch/arm/mach-tegra/pmc.c
@@ -4,6 +4,7 @@
  */
 
 #include <common.h>
+#include <cpu_func.h>
 
 #include <linux/arm-smccc.h>