mips: ath79: add AP143 reference board

This patch add board-level code and base DT for AP143.

Signed-off-by: Wills Wang <wills.wang@live.com>
[updated defconfig, enabled CONFIG_USE_PRIVATE_LIBGCC=y]
Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
diff --git a/board/qca/ap143/Makefile b/board/qca/ap143/Makefile
new file mode 100644
index 0000000..00f7837
--- /dev/null
+++ b/board/qca/ap143/Makefile
@@ -0,0 +1,5 @@
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+obj-y	= ap143.o