x86-userspace: Turn on SMP by default

A signigicant portion of x86 systems is SMP these days. Turn on the corresponding user space option to reflect the situation, specifically as running SMP-enabled libraries on a single-core system is just slightly suboptimal while the other way around does not work, forcing the user to rebuild the Xenomai libs.

---

 configure.in |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

index 4300d6f..d665dc6 100644
@@ -135,6 +135,9 @@ AC_MSG_RESULT(${debug_symbols:-no})
 dnl SMP support (default: off)
 
 CONFIG_SMP=
+if test $XENO_TARGET_ARCH = x86; then
+	CONFIG_SMP=y
+fi
 AC_MSG_CHECKING(for SMP support)
 AC_ARG_ENABLE(smp,
 	AS_HELP_STRING([--enable-smp], [Enable SMP support]),