arm: MediaTek: add basic support for MT7623 boards

This adds a general board file based on MT7623 SoCs from MediaTek.

As this u-boot is loaded by MTK proprietary preloader, there is no
low level initializtion codes.

Tested-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/board/mediatek/mt7623/MAINTAINERS b/board/mediatek/mt7623/MAINTAINERS
new file mode 100644
index 0000000..eeb0375
--- /dev/null
+++ b/board/mediatek/mt7623/MAINTAINERS
@@ -0,0 +1,7 @@
+MT7623
+M:	Ryder Lee <ryder.lee@mediatek.com>
+M:	Weijie Gao <weijie.gao@mediatek.com>
+S:	Maintained
+F:	board/mediatek/mt7623
+F:	include/configs/mt7623.h
+F:	configs/mt7623n_bpir2_defconfig