board: ti: j7200: Add board detection support for j7200

Add board detection support for j7200 common processor board.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Reviewed-by: Suman Anna <s-anna@ti.com>