dt-bindings: input: gpio-keys: accept also interrupt-extended

dt-bindings: input: gpio-keys: accept also interrupt-extended

Each key device node might have interrupts-extended instead of
interrupts property:

  fsl-ls1028a-kontron-sl28-var1.dtb: buttons0: power-button: 'anyOf' conditional failed, one must be fixed:
    'interrupts' is a required property
    'gpios' is a required property

Signed-off-by: Krzysztof Kozlowski <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Dmitry Torokhov <[email protected]>