xterm: disable with ARC external toolchain

This package fails when building with ARC external toolchain

Marking this with special comment "# ARC toolchain issue" as the package
is to be enabled as soon as the issue with the ARC toolchain is
resolved.

Fixes:
  http://autobuild.buildroot.net/results/28a/28a92049a6ceef005787c5779f77ecf3fe8ad642//

Signed-off-by: Vlad Zakharov <vzakhar@synopsys.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/xterm/Config.in

@@ -4,6 +4,8 @@ config BR2_PACKAGE_XTERM
 	select BR2_PACKAGE_XLIB_LIBXAW
 	depends on BR2_PACKAGE_XORG7
 	depends on BR2_USE_MMU # fork()
+	# ARC toolchain issue
+	depends on !BR2_TOOLCHAIN_EXTERNAL_SYNOPSYS_ARC
 	help
 	  xterm terminal emulator