x86: qemu: Expand ROM size

Expand the ROM for x86_64 to 2MB to make space for the font, as it is
already on the edge.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/board/emulation/qemu-x86/Kconfig b/board/emulation/qemu-x86/Kconfig
index 01dc1d4..34d665a 100644
--- a/board/emulation/qemu-x86/Kconfig
+++ b/board/emulation/qemu-x86/Kconfig
@@ -21,7 +21,8 @@
 	select X86_RESET_VECTOR
 	select QEMU
 	select QFW_PIO if CMD_QFW
-	select BOARD_ROMSIZE_KB_1024
+	select BOARD_ROMSIZE_KB_1024 if TARGET_QEMU_X86
+	select BOARD_ROMSIZE_KB_2048 if TARGET_QEMU_X86_64
 	imply VIRTIO_PCI
 	imply VIRTIO_NET
 	imply VIRTIO_BLK