x86: Don't try to run the VGA BIOS in 64-bit mode

This is not supported, so disable it for now.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/pci/pci_rom.c b/drivers/pci/pci_rom.c
index cd083f7..57204c4 100644
--- a/drivers/pci/pci_rom.c
+++ b/drivers/pci/pci_rom.c
@@ -334,7 +334,7 @@
 			goto err;
 #endif
 	} else {
-#ifdef CONFIG_X86
+#if defined(CONFIG_X86) && CONFIG_IS_ENABLED(X86_32BIT_INIT)
 		bios_set_interrupt_handler(0x15, int15_handler);
 
 		bios_run_on_x86(dev, (unsigned long)ram, vesa_mode,