dt-bindings: ps2-gpio: convert binding to json-schema

[Danilo Krummrich]

Changes since v1
================
  - binding as separate patch (driver patch will be sent outside the scope of
    this patch series)
  - fixes requested by Krzysztof
  - fix warnings/errors reported by 'make dt_binding_check'

Changes since v2
================
  - add the driver patch to enforce open drain GPIO flags again
  - fix additionalProperties: false

This series converts the ps2-gpio dt-binding to the json-schema.

Additionally, it documents (in the dt-binding) and enforces to flag the
given gpios as open drain, since the PS/2 bus is open drain by
definition.

Danilo Krummrich (3):
      dt-bindings: ps2-gpio: convert binding to json-schema
      dt-bindings: ps2-gpio: document bus signals open drain
      input: ps2-gpio: enforce GPIOs flag open drain

 Documentation/devicetree/bindings/serio/ps2-gpio.txt  | 23 -----------------------
 Documentation/devicetree/bindings/serio/ps2-gpio.yaml | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 drivers/input/serio/ps2-gpio.c                        |  9 +++++++--
 3 files changed, 71 insertions(+), 25 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/serio/ps2-gpio.txt
 create mode 100644 Documentation/devicetree/bindings/serio/ps2-gpio.yaml