faft_config: Add delay_powerinfo_stable config

Some CPUs undergo multiple power state changes during power on.
Add a config item indicating how long before the power state is stable.

BUG=b:165124883
TEST=Confirm that firmware_ECPowerButton test passes.

Change-Id: If9205ca3758476b1fa8aab7cee83ef584c56ef14
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/fw-testing-configs/+/2359878
Reviewed-by: Andrew McRae <amcrae@chromium.org>
Reviewed-by: Dana Goyette <dgoyette@chromium.org>
Commit-Queue: Andrew McRae <amcrae@chromium.org>
Tested-by: Andrew McRae <amcrae@chromium.org>
diff --git a/DEFAULTS.json b/DEFAULTS.json
index c21d1aa..a69fe1a 100644
--- a/DEFAULTS.json
+++ b/DEFAULTS.json
@@ -62,6 +62,9 @@
     "firmware_screen": 10,
     "firmware_screen.DOC": "Delay between power-on and firmware screen",
 
+    "delay_powerinfo_stable": 0,
+    "delay_powerinfo_stable.DOC": "Delay between AP power-on and when powerinfo is stable. Some CPUs have an internal reset that transitions through different power states.",
+
     "delay_reboot_to_ping": 30,
     "delay_reboot_to_ping.DOC": "Delay between reboot and first ping response from the DUT. When this times out, it indicates we're stuck at a firmware screen. Hence, bypass action has to be taken if we want to proceed.",
 
diff --git a/puff.json b/puff.json
index a082a99..39a0487 100644
--- a/puff.json
+++ b/puff.json
@@ -14,6 +14,7 @@
     ],
     "ec_forwards_short_pp_press": true,
     "ec_has_hibernate_cmd": false,
+    "delay_powerinfo_stable": 6,
     "delay_reboot_to_ping": 40,
     "custom_usb_enable_names": [
         "EN_PP5000_USB_VBUS"