arm: ethernut5: convert to generic board

Enable CONFIG_SYS_GENERIC_BOARD for the Ethernut 5 board.

Signed-off-by: Tim Schendekehl <tim.schendekehl@egnite.de>
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
diff --git a/include/configs/ethernut5.h b/include/configs/ethernut5.h
index c81fc44..4c69af6 100644
--- a/include/configs/ethernut5.h
+++ b/include/configs/ethernut5.h
@@ -12,6 +12,8 @@
 
 #include <asm/hardware.h>
 
+#define CONFIG_SYS_GENERIC_BOARD
+
 /* The first stage boot loader expects u-boot running at this address. */
 #define CONFIG_SYS_TEXT_BASE	0x27000000	/* 16MB available */