beagle: beagley-ai: env: Setup scripts for LED control

beagle: beagley-ai: env: Setup scripts for LED control

Most of the users of BeagleY-AI are headless OR do not use serial port.
In such cases, it is very useful for the device to provide some level of
indication to know what state their board is at.

Unfortunately, with a single LED (ignoring the :heartbeat), the
options are limited. This is a precursor patch to actually enabling
the LED options that will use the same in the follow on patches.

Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Bryan Brattlof <bb@ti.com>
Reviewed-by: Andrew Davis <afd@ti.com>