gdb: do not allow selecting the simulator on ARC

Forbid BR2_PACKAGE_HOST_GDB_SIM selection for the ARC architecture,
since the simulator is not supported on ARC.

Fixes:

 http://autobuild.buildroot.net/results/4a1cd9a0beaff34830fd0f0ec47c30eda0a42d54/

Signed-off-by: Vlad Zakharov <vzakhar@synopsys.com>
[Thomas: tweak commit log.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/gdb/Config.in.host

@@ -25,6 +25,7 @@ config BR2_PACKAGE_HOST_GDB_PYTHON
 
 config BR2_PACKAGE_HOST_GDB_SIM
 	bool "Simulator support"
+	depends on !BR2_arc
 	help
 	  This option enables the simulator support in the cross gdb.