anvl: Use the omap dieid passed from the install script

This makes the USB gadget to show the dieid also with
mass storage device appearing on PC host under:

/dev/disk/by-id/usb-Linux_File-Stor_Gadget_XXX-0:0

Where XXX is the dieid of the omap.

Signed-off-by: Tony Lindgren <tony@atomide.com>
anvl: Add a hook for running some basic tests on the hardware

This should contains tests that make installing the rootfs
fail. More complicated tests for wlan etc should be done
after the rootfs has been booted.

Signed-off-by: Tony Lindgren <tony@atomide.com>