fix(boards): Base config/overlay for rp2040 boards

Baseline config and overlay for the following:

* `rpi_pico`
* `adafruit_kb2040`
* `sparkfun_pro_micro_rp2040`
* `adafruit_qt_py_rp2040`
* `seeeduino_xiao_rp2040`
* `boardsource_blok`
* `01space_rp2040_042lcd`

Co-authored-by: Joel Spadin <joelspadin@gmail.com>

app/boards/adafruit_qt_py_rp2040.overlay

@@ -0,0 +1,9 @@
+/*
+ * Copyright (c) 2023 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "usb_console.dtsi"
+
+&xiao_serial { status = "disabled"; };