dt-bindings: Add vendor prefix and trivial device for BluTek BPA-RS600

Add vendor prefix "blutek" for BluTek Power.
Add trivial device entry for BPA-RS600.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210317040231.21490-1-chris.packham@alliedtelesis.co.nz


Signed-off-by: Guenter Roeck <linux@roeck-us.net>