dt-bindings: arm: add TQMa8Xx boards

dt-bindings: arm: add TQMa8Xx boards

TQMa8Xx is a SOM series featuring NXP i.MX8X SoC.
They are called TQMa8XQP and TQMa8XDP respectively.
MBa8Xx is an evaluation mainboard for this SOM

Signed-off-by: Markus Niebel <Markus.Niebel@tq-group.com>
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>