dt-bindings: altera: removal of generic PE1 dts

Remove the binding for the generic Mercury+ AA1 on PE1 carrier board.

The removed Mercury+ AA1 on PE1 carrier board is just a particular
setup case, which is actually replaced by the set of generic Mercury+
AA1 combinations patch.

In other words a combination of a Mercury+ AA1 on a PE1 base board,
with boot mode SD card is already covered by the generic AA1
combinations. There is no further reason to keep this particular case
now in a redundantly. Thus the redundant DT setup is removed.

Signed-off-by: Lothar Rubusch <[e-mail]>
Acked-by: Krzysztof Kozlowski <[e-mail]>
Signed-off-by: Dinh Nguyen <[e-mail]>

Documentation/devicetree/bindings/arm/altera.yaml

···
               - enclustra,mercury-aa1-pe1
               - enclustra,mercury-aa1-pe3
               - enclustra,mercury-aa1-st1
-              - enclustra,mercury-pe1
               - google,chameleon-v3
           - const: enclustra,mercury-aa1
           - const: altr,socfpga-arria10