Automate the usage of '--disable-gdbmi' to be used only with GDB versions less than 6.4, if they are even used anymore.

toolchain/gdb/gdb.mk

@@ -19,10 +19,16 @@ GDB_CAT:=bzcat
 
 GDB_DIR:=$(TOOL_BUILD_DIR)/gdb-$(GDB_VERSION)
 
-# NOTE: This option should not be used with newer gdb versions.
+# NOTE: This option should not be used with gdb versions 6.4 and above.
+ifeq ($(GDB_VERSION),6.2.1)
 DISABLE_GDBMI:=--disable-gdbmi
 endif
 
+ifeq ($(GDB_VERSION),6.3)
+DISABLE_GDBMI:=--disable-gdbmi
+endif
+endif
+
 $(DL_DIR)/$(GDB_SOURCE):
 	$(WGET) -P $(DL_DIR) $(GDB_SITE)/$(GDB_SOURCE)