qemu-x86: Enable SMP support

QEMU can do this for a while now.

Change-Id: I3a5027a7afc9dd18463d26cb42fe68747a89f6b0
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: https://review.coreboot.org/12656
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
diff --git a/src/cpu/qemu-x86/Kconfig b/src/cpu/qemu-x86/Kconfig
index 88cf82b..ea2bc46 100644
--- a/src/cpu/qemu-x86/Kconfig
+++ b/src/cpu/qemu-x86/Kconfig
@@ -19,3 +19,4 @@
 	select ARCH_VERSTAGE_X86_32
 	select ARCH_ROMSTAGE_X86_32
 	select ARCH_RAMSTAGE_X86_32
+	select SMP