arm: socfpga: rst: add register definition for cold reset

This adds a define for the bit in rstmgr's ctrl regiser that issues
a cold reset (we had a define for the warm reset bit only) in preparation
for a proper sysrese driver.
Signed-off-by: NSimon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Series changes: 2
- separate this patch to the register descriptions from the actual
  sysreset driver patch

arch/arm/mach-socfpga/include/mach/reset_manager.h

@@ -11,6 +11,7 @@ void reset_cpu(ulong addr);
 void socfpga_per_reset(u32 reset, int set);
 void socfpga_per_reset_all(void);
 
+#define RSTMGR_CTRL_SWCOLDRSTREQ_LSB 0
 #define RSTMGR_CTRL_SWWARMRSTREQ_LSB 1
 
 /*