Update power on timeout for PLDM test

Changes:
    - Replace hard coded timeout with power_on_timeout

Tested:
    - NA

Change-Id: I93e39f9ab516c4390440a0e7e437a66bd0beb0b9
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/pldm/test_firmware_boot_side.robot b/pldm/test_firmware_boot_side.robot
index 0e55717..3d656f1 100755
--- a/pldm/test_firmware_boot_side.robot
+++ b/pldm/test_firmware_boot_side.robot
@@ -83,7 +83,8 @@
 
         Print Timen  BMC rebooted, wait for host to boot to Runtime.
         # Post BMC reset, host should auto power on back to runtime.
-        Wait Until Keyword Succeeds  10 min  20 sec  Is Boot Progress Runtime Matched
+        Wait Until Keyword Succeeds  ${power_on_timeout}  20 sec
+        ...  Is Boot Progress Runtime Matched
 
         # Verify the system is booting up with the new fw_boot_side set.
         ${cur_boot_side}=  PLDM Get BIOS Attribute  fw_boot_side