dt-bindings: arm: add TQ boards

MBa is a series of Carrier Boards / Single Board Computers (SBC) for
evaluation of TQMa SoMs.
The MBa7 carrier board can only interface with TQMa7 modules.
The TQMa7 module can only be mounted with NXP i.MX7 Solo or Dual SoCs.
Primary compatible strings are of the form "tq,<SoC>-<SBC>".

Signed-off-by: Bruno Thomsen <bruno.thomsen@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>