Add Elite-Pi converter (#18236)

Co-authored-by: Joel Challis <git@zvecr.com>

platforms/chibios/converters/promicro_to_elite_pi/_pin_defs.h

@@ -0,0 +1,36 @@
+// Copyright 2022 QMK
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+// Left side (front)
+#define D3 0U
+#define D2 1U
+//      GND
+//      GND
+#define D1 2U
+#define D0 3U
+#define D4 4U
+#define C6 5U
+#define D7 6U
+#define E6 7U
+#define B4 8U
+#define B5 9U
+
+// Right side (front)
+//      RAW
+//      GND
+//      RESET
+//      VCC
+#define F4 29U
+#define F5 28U
+#define F6 27U
+#define F7 26U
+#define B1 22U
+#define B3 20U
+#define B2 23U
+#define B6 21U
+
+// LEDs
+#define D5 12U
+#define B0 13U

platforms/chibios/converters/promicro_to_elite_pi/converter.mk

@@ -0,0 +1,9 @@
+# Elite-Pi MCU settings for converting AVR projects
+MCU := RP2040
+BOARD := QMK_PM2040
+BOOTLOADER := rp2040
+
+# These are defaults based on what has been implemented for RP2040 boards
+SERIAL_DRIVER ?= vendor
+WS2812_DRIVER ?= vendor
+BACKLIGHT_DRIVER ?= software