emulation/qemu-i440fx: Use a 4MB ROM by default

At present the default ROM for for QEMU is too small for U-Boot to fit.
Add a condition to catch this and expand it to a 1MB ROM. This allows
booting U-Boot under emulation.

It also matches the size used by other emulation boards.

Signed-off-by: Simon Glass <sjg@chromium.org>
Change-Id: Ia1a8c1109e3ece5fec56255173a2d19d4a130bcb
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59604
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
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 436bb20..f02c92d 100644
--- a/src/mainboard/emulation/qemu-i440fx/Kconfig
+++ b/src/mainboard/emulation/qemu-i440fx/Kconfig
@@ -9,7 +9,7 @@
 	select HAVE_CMOS_DEFAULT
 	select HAVE_PIRQ_TABLE
 	select HAVE_ACPI_TABLES
-	select BOARD_ROMSIZE_KB_256 if !VBOOT
+	select BOARD_ROMSIZE_KB_4096 if !VBOOT
 	select BOARD_ROMSIZE_KB_16384 if VBOOT
 	select MAINBOARD_HAS_NATIVE_VGA_INIT
 	select MAINBOARD_FORCE_NATIVE_VGA_INIT