Add Default Toolchain revision if not defined in BoardConfig.mk
diff --git a/core/combo/TARGET_linux-arm.mk b/core/combo/TARGET_linux-arm.mk
index c0b7609..8b7e1de 100644
--- a/core/combo/TARGET_linux-arm.mk
+++ b/core/combo/TARGET_linux-arm.mk
@@ -34,6 +34,15 @@
TARGET_ARCH_VARIANT := armv5te
endif
+ifndef ($(strip $(TARGET_GCC_VERSION_ARM)),)
+TARGET_GCC_VERSION_ARM := 4.7
+endif
+
+ifndefeq ($(strip $(TARGET_GCC_VERSION_AND)),)
+TARGET_GCC_VERSION_AND := 4.7
+endif
+
+
TARGET_ARCH_SPECIFIC_MAKEFILE := $(BUILD_COMBOS)/arch/$(TARGET_ARCH)/$(TARGET_ARCH_VARIANT).mk
ifeq ($(strip $(wildcard $(TARGET_ARCH_SPECIFIC_MAKEFILE))),)
$(error Unknown ARM architecture version: $(TARGET_ARCH_VARIANT))