toradex: tdx-cfg-block: Use official SKU names

Up to now in the code we named Toradex SKUs in a slightly different way
compared to the official product name, start using the official names
from now on to avoid misunderstanding.

This has also the nice benefit of the string being shorter, allowing
to fit nicely in 80 columns even adding the product ID when printing
the hardware information.

Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>