emulation/qemu-x86: Select BOOT_DEVICE_NOT_SPI_FLASH

SPI flash is not emulated on these boards.

Change-Id: If29a87441cb26e53c9814ed10ddcfe14752c3965
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/52791
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/emulation/qemu-i440fx/Kconfig b/src/mainboard/emulation/qemu-i440fx/Kconfig
index b1b2f45..19f0fca 100644
--- a/src/mainboard/emulation/qemu-i440fx/Kconfig
+++ b/src/mainboard/emulation/qemu-i440fx/Kconfig
@@ -15,6 +15,7 @@
 	select MAINBOARD_FORCE_NATIVE_VGA_INIT
 	select HAVE_ASAN_IN_ROMSTAGE
 	select NO_SMM
+	select BOOT_DEVICE_NOT_SPI_FLASH
 
 config VBOOT
 	select VBOOT_MUST_REQUEST_DISPLAY