Initial changes for reboot log

- Adding reboot log using the existing mechanism
- Adding reboot_cnt as a config variable (Currently writable for
  debugging purposes - would make it read only later)
  Stored using fcb - future work would be to make this optional to be
  stored using fcb or NFFS
- Adding reasons for reboot - HARD reboot and SOFT reboot. There is an
  unknown reason as well if the chip decides to give us reasons for a
  reboot
- Since a hard reboot is detected before the OS starts the timestamp for
  it is going to be 0

- I can clean it up as required

Example of reboot log entries:
0 usecs, 2 > REBOOT: CRITICAL: rsn:HARD, cnt:13, img:255.255.65535.4294967295
12441000 usecs, 2 > REBOOT: CRITICAL: rsn:SOFT, cnt:14, img:255.255.65535.4294967295

1 files changed, 12 insertions, 1 deletions

diff --git a/sys/config/src/config.c b/sys/config/src/config.c
index bc6bf77a..c21cec74 100644
--- a/sys/config/src/config.c
+++ b/sys/config/src/config.c
@@ -28,17 +28,28 @@
 
 struct conf_handler_head conf_handlers = SLIST_HEAD_INITIALIZER(&conf_handlers);
 
+static uint8_t conf_cmd_inited;
+
 int
 conf_init(void)
 {
-    int rc = 0;
+    int rc;
 
+    rc = 0;
+    if (conf_cmd_inited) {
+        goto done;
+    }
 #ifdef SHELL_PRESENT
     rc = conf_cli_register();
 #endif
 #ifdef NEWTMGR_PRESENT
     rc = conf_nmgr_register();
 #endif
+    if (!rc) {
+        conf_cmd_inited = 1;
+    }
+
+done:
     return rc;
 }