selfboot: Don't include unneeded ip_checksum.h

Change-Id: I09b888e70f7432f7025b0b851acfb0279553400f
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/426
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>

src/boot/selfboot.c

@@ -24,7 +24,6 @@
 #include <boot/elf.h>
 #include <boot/elf_boot.h>
 #include <boot/coreboot_tables.h>
-#include <ip_checksum.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>