cpu/qemu-x86: Add the option to have no SMM

Qemu i440fx does not support an smihandler at the moment.

Change-Id: I5526b19b8294042a49e5bca61036e47db01fd28a
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/48208
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>

src/cpu/qemu-x86/Kconfig

@@ -5,10 +5,29 @@ config CPU_QEMU_X86
 	select UDELAY_TSC
 	select TSC_MONOTONIC_TIMER
 	select UNKNOWN_TSC_RATE
-	select SMM_ASEG
 
 if CPU_QEMU_X86
 
+# coreboot i440fx does not support SMM
+choice
+	prompt "SMM support"
+	default CPU_QEMU_X86_ASEG_SMM
+	depends on BOARD_EMULATION_QEMU_X86_Q35
+
+config CPU_QEMU_X86_NO_SMM
+	bool "No SMM"
+	select NO_SMM
+
+config CPU_QEMU_X86_ASEG_SMM
+	bool "SMM in ASEG"
+	select SMM_ASEG
+
+#config CPU_QEMU_X86_TSEG_SMM
+#	bool "SMM in TSEG"
+#	select SMM_TSEG
+
+endchoice
+
 config CPU_QEMU_X86_64
 	bool "Experimental 64bit support"
 	select ARCH_ALL_STAGES_X86_64