supertuxkart: Constrain to x86 architecture

Our build system has detected that angelscript can't be
cross-compiled properly. This has been also reported to
supertuxkart [1], and although the developers were open
to take patches fixing STK embedded angelscript, it was
pointed out that non-x86 architectures were not officially
supported and of little interest [2].

Hence, let's constrain the package selection and the host
architecture to x86.

[1] https://github.com/supertuxkart/stk-code/issues/2569
[2] https://github.com/supertuxkart/stk-code/pull/2195

Fixes: http://autobuild.buildroot.net/results/655/655f046b3bb5f7a4ea492328b608e409d6769689/
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/supertuxkart/Config.in

@@ -1,5 +1,7 @@
 config BR2_PACKAGE_SUPERTUXKART
 	bool "supertuxkart"
+	depends on BR2_HOSTARCH = "x86_64" || BR2_HOSTARCH = "x86"
+	depends on BR2_i386 || BR2_x86_64
 	depends on BR2_USE_MMU # fork()
 	depends on BR2_INSTALL_LIBSTDCPP # openal
 	depends on BR2_TOOLCHAIN_HAS_THREADS_NPTL # openal
@@ -25,6 +27,8 @@ config BR2_PACKAGE_SUPERTUXKART
 	  http://supertuxkart.sourceforge.net/Main_Page
 
 comment "supertuxkart needs an OpenGL backend, a uClibc or glibc toolchain w/ NPTL, C++"
+	depends on BR2_HOSTARCH = "x86_64" || BR2_HOSTARCH = "x86"
+	depends on BR2_i386 || BR2_x86_64
 	depends on BR2_USE_MMU
 	depends on BR2_PACKAGE_OPENAL_ARCH_SUPPORTS
 	depends on BR2_PACKAGE_XORG7