ibm: Add power button GPIO definition

This allows a power button press to power on the system.  Rainier and
Everest use the same GPIO.

Tested: Button was pressed and the system booted.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: Ib8f373dda2adb5575f2a0001d986962e5430fba5
diff --git a/meta-ibm/recipes-phosphor/skeleton/obmc-libobmc-intf/p10bmc/gpio_defs.json b/meta-ibm/recipes-phosphor/skeleton/obmc-libobmc-intf/p10bmc/gpio_defs.json
index 2960395..654be09 100644
--- a/meta-ibm/recipes-phosphor/skeleton/obmc-libobmc-intf/p10bmc/gpio_defs.json
+++ b/meta-ibm/recipes-phosphor/skeleton/obmc-libobmc-intf/p10bmc/gpio_defs.json
@@ -25,6 +25,11 @@
             "name": "SYS_PWROK_BUFF",
             "pin": "R2",
             "direction": "in"
+        },
+        {
+            "name": "POWER_BUTTON",
+            "pin": "P3",
+            "direction": "both"
         }
     ]
 }