board: nx25-ae250: Rename as ax25-ae350

Rename
 nx25 as ax25
 ae250 as ae350
 nx25-ae250 as ax25-ae350
 including filename, variable, string and definition.

Signed-off-by: Rick Chen <rick@andestech.com>
Signed-off-by: Rick Chen <rickchen36@gmail.com>
Cc: Greentime Hu <green.hu@gmail.com>
diff --git a/board/AndesTech/ax25-ae350/MAINTAINERS b/board/AndesTech/ax25-ae350/MAINTAINERS
new file mode 100644
index 0000000..508c6ac
--- /dev/null
+++ b/board/AndesTech/ax25-ae350/MAINTAINERS
@@ -0,0 +1,6 @@
+AX25-AE350 BOARD
+M:	Rick Chen <rick@andestech.com>
+S:	Maintained
+F:	board/AndesTech/ax25-ae350/
+F:	include/configs/ax25-ae350.h
+F:	configs/ax25-ae350_defconfig