x86: Add support for running option ROMs natively

On x86 machines we can use an emulator to run option ROMS as with other
architectures. But with some additional effort (mostly due to the 16-bit
nature of option ROMs) we can run them natively. Add support for this.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index e146e64..55de788 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -5,6 +5,9 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
+obj-y += bios.o
+obj-y += bios_asm.o
+obj-y += bios_interrupts.o
 obj-$(CONFIG_CMD_BOOTM) += bootm.o
 obj-y	+= cmd_boot.o
 obj-y	+= gcc.o