sencha: correct irq numbering

Replace the made-up numbering used during initial bringup with the
correct matcha-derived assignments.

Change-Id: I4670ef2c6c3b4a051d3c6c80b5a165576eb1c1da

sdk/boards/sencha.json

diff --git a/sdk/boards/sencha.json b/sdk/boards/sencha.json
index 7d81dbe..4c2d755 100644
--- a/sdk/boards/sencha.json
+++ b/sdk/boards/sencha.json
@@ -43,39 +43,43 @@
     },
     "interrupts": [
         {
-            "name": "UARTInterrupt",
-            "number": 2,
-            "priority": 3,
-            "edge_triggered": true
-        },
-        {
             "name": "I2sRxWatermarkInterrupt",
-            "number": 3,
+            "number": 40,
             "priority": 3
         },
         {
             "name": "I2sTxWatermarkInterrupt",
-            "number": 4,
+            "number": 39,
             "priority": 3
         },
         {
             "name": "I2sTxEmptyInterrupt",
-            "number": 5,
+            "number": 41,
             "priority": 3
         },
         {
             "name": "MlTopFinishInterrupt",
-            "number": 6,
+            "number": 34,
             "priority": 3
         },
         {
             "name": "MlTopFaultInterrupt",
-            "number": 7,
+            "number": 35,
+            "priority": 3
+        },
+        {
+            "name": "MailboxWtInterrupt",
+            "number": 30,
             "priority": 3
         },
         {
             "name": "MailboxRtInterrupt",
-            "number": 8,
+            "number": 31,
+            "priority": 3
+        },
+        {
+            "name": "MailboxEInterrupt",
+            "number": 32,
             "priority": 3
         }
     ],