dt-bindings: arm: Move Emtrion i.MX6 board bindings to schema

The Emtrion board bindings landed when the i.MX board/SoC bindings were
being converted to DT schema. Add them to the schema and remove the
separate file.

Cc: Jan Tuerk <jan.tuerk@emtrion.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: NRob Herring <robh@kernel.org>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

Documentation/devicetree/bindings/arm/emtrion.txt

-Emtrion Devicetree Bindings
-===========================
-
-emCON Series:
--------------
-
-Required root node properties
-	- compatible:
-	- "emtrion,emcon-mx6", "fsl,imx6q"; 		: emCON-MX6D or emCON-MX6Q SoM
-	- "emtrion,emcon-mx6-avari", "fsl,imx6q";	: emCON-MX6D or emCON-MX6Q SoM on Avari Base
-	- "emtrion,emcon-mx6", "fsl,imx6dl"; 		: emCON-MX6S or emCON-MX6DL SoM
-	- "emtrion,emcon-mx6-avari", "fsl,imx6dl";	: emCON-MX6S or emCON-MX6DL SoM on Avari Base

Documentation/devicetree/bindings/arm/fsl.yaml

@@ -80,6 +80,8 @@ properties:
       - description: i.MX6Q based Boards
         items:
           - enum:
+              - emtrion,emcon-mx6         # emCON-MX6D or emCON-MX6Q SoM
+              - emtrion,emcon-mx6-avari   # emCON-MX6D or emCON-MX6Q SoM on Avari Base
               - fsl,imx6q-arm2
               - fsl,imx6q-sabreauto
               - fsl,imx6q-sabrelite
@@ -99,6 +101,8 @@ properties:
         items:
           - enum:
               - eckelmann,imx6dl-ci4x10
+              - emtrion,emcon-mx6         # emCON-MX6S or emCON-MX6DL SoM
+              - emtrion,emcon-mx6-avari   # emCON-MX6S or emCON-MX6DL SoM on Avari Base
               - fsl,imx6dl-sabreauto      # i.MX6 DualLite/Solo SABRE Automotive Board
               - fsl,imx6dl-sabresd        # i.MX6 DualLite SABRE Smart Device Board
               - technologic,imx6dl-ts4900