gnss: add 8122 AT set command

Change-Id: Ia406f06244ec0ff7570744113e31224d99330165
diff --git a/mbtk/mbtk_gnssd/gnss_hd8122.h b/mbtk/mbtk_gnssd/gnss_hd8122.h
index 7df7e7a..1917ff1 100755
--- a/mbtk/mbtk_gnssd/gnss_hd8122.h
+++ b/mbtk/mbtk_gnssd/gnss_hd8122.h
@@ -47,6 +47,7 @@
 typedef enum {
     HD8122_ID_CFG_PRT = 0x00,
     HD8122_ID_CFG_MSG = 0x01,
+    HD8122_ID_CFG_COORD = 0x06,
     HD8122_ID_CFG_PPS = 0x07,
     HD8122_ID_CFG_CFG = 0x09,
     HD8122_ID_CFG_DOP = 0x0A,