[Bsp][qemu-vexpress-gemini]fix build error with gcc

Author: lymzzyh

.travis.yml

@@ -60,6 +60,7 @@ env:
 #  - RTT_BSP='nios_ii' # no scons
 #  - RTT_BSP='pic32ethernet' # no scons
   - RTT_BSP='qemu-vexpress-a9' RTT_TOOL_CHAIN='sourcery-arm'
+  - RTT_BSP='qemu-vexpress-gemini' RTT_TOOL_CHAIN='sourcery-arm'
   - RTT_BSP='sam7x' RTT_TOOL_CHAIN='sourcery-arm'
 #  - RTT_BSP='simulator' # x86
   - RTT_BSP='stm32f0x' RTT_TOOL_CHAIN='sourcery-arm' 

bsp/qemu-vexpress-gemini/SConstruct

@@ -5,7 +5,7 @@ import rtconfig
 if os.getenv('RTT_ROOT'):
     RTT_ROOT = os.getenv('RTT_ROOT')
 else:
-    RTT_ROOT = os.path.normpath(os.getcwd() + '/rt-thread')
+    RTT_ROOT = os.path.normpath(os.getcwd() + '/../..')
 
 sys.path = sys.path + [os.path.join(RTT_ROOT, 'tools')]
 from building import *