mdm9615: Disable thumb mode for 9x15

The 9x15 builds crash when the assembly files are compiled
with thumb mode for the 2011.03 toolchain.

Change-Id: I69f8227cef9d0efbc3c244560bec5418e0a0ae54
diff --git a/project/mdm9615.mk b/project/mdm9615.mk
index da0b34e..08a4866 100644
--- a/project/mdm9615.mk
+++ b/project/mdm9615.mk
@@ -9,3 +9,6 @@
 #DEFINES += WITH_DEBUG_DCC=1
 DEFINES += WITH_DEBUG_UART=1
 #DEFINES += WITH_DEBUG_FBCON=1
+
+#disable Thumb mode for the codesourcery/arm-2011.03 toolchain
+ENABLE_THUMB := false