Merge pull request ARMmbed#122 from ARMmbed/LiyouZhou-patch-1

Guard sdblockdevice instantiation

Author: bogdanm

source/main.cpp

@@ -55,7 +55,7 @@ extern ARM_UC_PAAL_UPDATE MBED_CLOUD_CLIENT_UPDATE_STORAGE;
 #error Update client storage must be defined in user configuration file
 #endif
 
-#if MBED_CLOUD_CLIENT_UPDATE_STORAGE == ARM_UCP_FLASHIAP_BLOCKDEVICE
+#if defined(ARM_UC_USE_PAL_BLOCKDEVICE) && (ARM_UC_USE_PAL_BLOCKDEVICE==1)
 #include "SDBlockDevice.h"
 
 /* initialise sd card blockdevice */