Don't pass -m32/-m64 where it's not supported.

Only PowerPC, SPARC, and x86 do support the -m32 and -m64 compiler options [1].

Rather then excluding all architectures not supporting these options as it is
done in commit c063434 [2], include all
architectures that do support them.

This will fix building Boost for the SuperH architecture with Buildroot [3].

[1] https://gcc.gnu.org/onlinedocs/gcc/Option-Summary.html
[2] c063434
[3] http://autobuild.buildroot.net/results/ccd/ccd5c83963032ba49b1627b1dff39e34a9486943/build-end.log

src/tools/gcc.jam

@@ -451,7 +451,7 @@ rule setup-address-model ( targets * : sources * : properties * )
         else
         {
             local arch = [ feature.get-values architecture : $(properties) ] ;
-            if $(arch) != arm && $(arch) != mips1
+            if $(arch) = power || $(arch) = sparc || $(arch) = x86
             {
                 if $(model) = 32
                 {