dt-bindings: display: ti: Fix compatible for am62a7 dss

Fix incorrect format of compatible string (comma instead of hyphen) for
TI's AM62A7 SoC.

s/ti,am62a7,dss/ti,am62a7-dss

Fixes: 7959ceb767e4 ("dt-bindings: display: ti: Add support for am62a7 dss")
Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Signed-off-by: Devarsh Thakkar <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Rob Herring (Arm) <[e-mail]>

Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml

···
   compatible:
     enum:
       - ti,am625-dss
-      - ti,am62a7,dss
+      - ti,am62a7-dss
       - ti,am65x-dss
 
   reg: