gdb: not available on NIOS II

The mainline gdb does not have support for NIOS II, even just for
gdbserver.

Fixes:

  http://autobuild.buildroot.org/results/e57/e57aa016d6a73e59c404a7eb43c7bf5c16cbcbdc/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/gdb/Config.in

@@ -1,5 +1,5 @@
 comment "gdb/gdbserver needs a toolchain w/ threads, threads debug"
-	depends on !BR2_aarch64
+	depends on !BR2_aarch64 && !BR2_nios2
 	depends on !BR2_TOOLCHAIN_HAS_THREADS || !BR2_TOOLCHAIN_HAS_THREADS_DEBUG
 
 config BR2_PACKAGE_GDB
@@ -10,7 +10,7 @@ config BR2_PACKAGE_GDB
 	select BR2_PACKAGE_GDB_SERVER if \
 	       (!BR2_PACKAGE_GDB_DEBUGGER && !BR2_TOOLCHAIN_EXTERNAL_GDB_SERVER_COPY)
 	depends on BR2_TOOLCHAIN_HAS_THREADS && BR2_TOOLCHAIN_HAS_THREADS_DEBUG
-	depends on !BR2_aarch64
+	depends on !BR2_aarch64 && !BR2_nios2
 	help
 	  GDB, the GNU Project debugger, allows you to see what is
 	  going on `inside' another program while it executes -- or