strace: disable unsupported nios2 arch

Fixes
http://autobuild.buildroot.net/results/88f330254a83fbc105a74e76df586672d2c369c4/

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/strace/Config.in

@@ -1,6 +1,6 @@
 config BR2_PACKAGE_STRACE
 	bool "strace"
-	depends on !BR2_arc
+	depends on !BR2_arc && !BR2_nios2
 	help
 	  A useful diagnostic, instructional, and debugging tool.
 	  Allows you to track what system calls a program makes