toolchain: gdb: Disable tests

Instead of patching the tests out, just remove them with a configure
option.
No files were generates in the testsuite and unit-test directories.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

toolchain/gdb/Makefile

@@ -36,6 +36,8 @@ HOST_CONFIGURE_ARGS = \
 	--enable-threads \
 	--with-expat \
 	--without-python \
+	--disable-unit-tests \
+	--disable-ubsan \
 	--disable-binutils \
 	--disable-ld \
 	--disable-gas \