Use custom GRUB2 config file on x86

We'll be overriding them for redundant boot later on. For now, just
let's rely on the default console and place it on tty0 for better QEMU
experience.

Change-Id: I987348484baa55d05b0881408ce8cb4d74c3c00c
diff --git a/board/czechlight/epia_geode/overlay/boot/grub/grub.cfg b/board/czechlight/epia_geode/overlay/boot/grub/grub.cfg
new file mode 100644
index 0000000..243cd75
--- /dev/null
+++ b/board/czechlight/epia_geode/overlay/boot/grub/grub.cfg
@@ -0,0 +1,6 @@
+set default="0"
+set timeout="3"
+
+menuentry "CzechLight" {
+	linux /boot/bzImage root=/dev/sda1
+}