bsp/stm32f429-apollo:fix drv_i2c.c scons build error

Signed-off-by: Nluo jiao <luojiaoxy@163.com>

bsp/stm32f429-apollo/drivers/SConscript

@@ -21,7 +21,11 @@ if GetDepend('RT_USING_MTD_NAND'):
 
 # add Ethernet drivers.
 if GetDepend('RT_USING_LWIP'):
-    src += ['drv_eth.c', 'drv_i2c.c', 'drv_pcf8574.c']
+    src += ['drv_eth.c', 'drv_pcf8574.c']
+
+# add i2c drivers.
+if GetDepend(['RT_USING_I2C']) or GetDepend('RT_USING_LWIP'):
+    src += ['drv_i2c.c']
 
 # add gpio drivers.
 if GetDepend('RT_USING_PIN'):
@@ -38,10 +42,6 @@ if GetDepend('RT_USING_SFUD'):
 # add lcd drivers.
 if GetDepend('PKG_USING_GUIENGINE'):
     src += ['drv_lcd.c']
-
-# add i2c drivers.
-if GetDepend(['RT_USING_I2C']):
-    src += ['drv_i2c.c']
  
 CPPPATH = [cwd]