[VOL-2818][VOL-2745]:OLT soft reboot for DT and ATT

Change-Id: I07230cd208a92aec27737e0c98e34a969ebc098d
diff --git a/libraries/voltctl.robot b/libraries/voltctl.robot
index acbe3f5..0051e28 100644
--- a/libraries/voltctl.robot
+++ b/libraries/voltctl.robot
@@ -63,6 +63,13 @@
     ...    ${VOLTCTL_CONFIG}; voltctl device delete ${device_id}
     Should Be Equal As Integers    ${rc}    0
 
+Reboot Device
+    [Arguments]    ${device_id}
+    [Documentation]    Reboot the OLT using voltctl command
+    ${rc}    ${output}=    Run and Return Rc and Output
+    ...    ${VOLTCTL_CONFIG}; voltctl device reboot ${device_id}
+    Should Be Equal As Integers    ${rc}    0
+
 Disable Devices In Voltha
     [Documentation]    Disables all the known devices in voltha
     [Arguments]    ${filter}