update pico-sdk to 1.3.1

dhalbert · dhalbert · commit e852b28bb234 · 2022-05-20T17:52:35.000-04:00
diff --git a/ports/raspberrypi/sdk b/ports/raspberrypi/sdk
@@ -1 +1 @@
-Subproject commit 2062372d203b372849d573f252cf7c6dc2800c0a
+Subproject commit 426e46126b5a1efaea4544cdb71ab81b61983034
