Convert bootup code (int18/int19) to 32bit mode.

The boot entry points should not require 16bit mode, so use 32bit mode
    instead.
diff --git a/Makefile b/Makefile
index caf3fcc..30a3943 100644
--- a/Makefile
+++ b/Makefile
@@ -8,10 +8,10 @@
 OUT=out/
 
 # Source files
-SRCBOTH=output.c util.c floppy.c ata.c system.c mouse.c kbd.c pci.c boot.c \
-        serial.c clock.c pic.c
-SRC16=$(SRCBOTH) disk.c cdrom.c apm.c pcibios.c
-SRC32=$(SRCBOTH) post.c shadow.c post_menu.c memmap.c coreboot.c \
+SRCBOTH=output.c util.c floppy.c ata.c system.c mouse.c kbd.c pci.c \
+        serial.c clock.c pic.c cdrom.c
+SRC16=$(SRCBOTH) disk.c apm.c pcibios.c
+SRC32=$(SRCBOTH) post.c shadow.c post_menu.c memmap.c coreboot.c boot.c \
       acpi.c pirtable.c smm.c smpdetect.c mptable.c smbios.c pciinit.c
 TABLESRC=font.c cbt.c floppy_dbt.c