veyron: set reset_recovery to 0.5s in servo_veyron_overlay.xml

The default reset_recovery is zero, which means there isn't any delay
after sending cold_reset, warm_reset, or reboot cmd to EC, leading to
`dut-control power_state:rec` fail to boot in recovery mode.

Not sure, but 0.5s make power_state:rec work.

BUG=chrome-os-partner:33451,chrome-os-partner:33407
TEST=run 'cros_workon --host start hdctools'
         'sudo emerge hdctools'
         'sudo servod --board veyron -c veyron_r2.xml&'
         'dut-control power_state:rec'
     pinky-rev2 boots in recovery mode.

Change-Id: Idb7d650421c9399805f366ac095757656bcf2239
Reviewed-on: https://chromium-review.googlesource.com/231615
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Gediminas Ramanauskas <gedis@chromium.org>
Commit-Queue: Shunqian Zheng <zhengsq@rock-chips.com>
Tested-by: Shunqian Zheng <zhengsq@rock-chips.com>
diff --git a/servo/data/servo_veyron_overlay.xml b/servo/data/servo_veyron_overlay.xml
index 68e9dae..c1d41c0 100644
--- a/servo/data/servo_veyron_overlay.xml
+++ b/servo/data/servo_veyron_overlay.xml
@@ -9,6 +9,7 @@
   <control>
     <name>power_state</name>
     <doc>Used to turn the DUT off and on</doc>
-    <params clobber_ok="" cmd="set" shutdown_ec_command="power off"/>
+    <params clobber_ok="" cmd="set" shutdown_ec_command="power off"
+            reset_recovery="0.5"/>
   </control>
 </root>