bootstd: Add a simple bootmeth for ChromiumOS

It is possible to boot x86-based ChromeOS machines by parsing a table and
locating the kernel and command line. Add a bootmeth for this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/boot/Makefile b/boot/Makefile
index f828f87..10f0157 100644
--- a/boot/Makefile
+++ b/boot/Makefile
@@ -27,6 +27,7 @@
 obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_EXTLINUX) += bootmeth_extlinux.o
 obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_EXTLINUX_PXE) += bootmeth_pxe.o
 obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_EFILOADER) += bootmeth_efi.o
+obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_CROS) += bootmeth_cros.o
 obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_SANDBOX) += bootmeth_sandbox.o
 obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_SCRIPT) += bootmeth_script.o
 ifdef CONFIG_$(SPL_TPL_)BOOTSTD_FULL