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/arch/mips/mach-ath79/Kconfig b/arch/mips/mach-ath79/Kconfig
index c3012f8..f45403b 100644
--- a/arch/mips/mach-ath79/Kconfig
+++ b/arch/mips/mach-ath79/Kconfig
@@ -29,8 +29,13 @@
 	bool "AP121 Reference Board"
 	select SOC_AR933X
 
+config TARGET_AP143
+	bool "AP143 Reference Board"
+	select SOC_QCA953X
+
 endchoice
 
 source "board/qca/ap121/Kconfig"
+source "board/qca/ap143/Kconfig"
 
 endmenu