add RB_SW_SUSPEND and RB_KEXEC to sys/reboot.h

using the glibc names for the magic constants of the linux reboot syscall

include/sys/reboot.h

@@ -9,6 +9,8 @@ extern "C" {
 #define RB_ENABLE_CAD   0x89abcdef
 #define RB_DISABLE_CAD  0
 #define RB_POWER_OFF    0x4321fedc
+#define RB_SW_SUSPEND   0xd000fce2
+#define RB_KEXEC        0x45584543
 
 int reboot(int);