perl: Enable CONFIG_PERL_THREADS properly by default for x86

Signed-off-by: Marcel Denia <naoir@gmx.net>

lang/perl/Config.in

 
 config PERL_THREADS
     bool "Enable threading support"
-    default y if (mips || mipsel || x86 || x86_64 || armeb || arm) && (USE_UCLIBC || USE_EGLIBC)
+    default y if (mips || mipsel || i386 || i686 || x86_64 || armeb || arm) && (USE_UCLIBC || USE_EGLIBC)
     default n
 
 config PERL_TESTS