[bugfix] Open the #define RT_USING_LWIP in rtconfig.h , then build it , the stm32_eth.h can not find.

Signed-off-by: pangwei <271372443@qq.com>

bsp/stm32f40x/applications/application.c

@@ -20,7 +20,7 @@
 #include <lwip/sys.h>
 #include <lwip/api.h>
 #include <netif/ethernetif.h>
-#include "stm32_eth.h"
+#include "stm32f4xx_eth.h"
 #endif
 
 #ifdef RT_USING_GDB

bsp/stm32f40x/drivers/SConscript

@@ -3,9 +3,25 @@ Import('rtconfig')
 from building import *
 
 cwd     = os.path.join(str(Dir('#')), 'drivers')
-src	= Glob('*.c')
+
+# add the general drivers.
+src = Split("""
+board.c
+stm32f4xx_it.c
+usart.c
+""")
+
+# add Ethernet drivers.
+if GetDepend('RT_USING_LWIP'):
+    src += ['stm32f4xx_eth.c']
+
+# add gpio drivers.
+if GetDepend('RT_USING_PIN'):
+    src += ['gpio.c']
+
 CPPPATH = [cwd]
 
 group = DefineGroup('Drivers', src, depend = [''], CPPPATH = CPPPATH)
 
 Return('group')
+