fsl-spi.txt contains the bindings for the fsl,spi and fsl,espi
contollers. Convert them to YAML.

Signed-off-by: J. Neuschäfer <redacted>
---

V2:
- add missing end-of-document ("...") markers
- add missing constraints to interrupts, fsl,espi-num-chipselects,
  fsl,csbef and fsl,csaft properties
- remove unnecessary type from clock-frequency property
- fix property order to comply with dts coding style
---
 .../devicetree/bindings/spi/fsl,espi.yaml          | 64 +++++++++++++++++++
 Documentation/devicetree/bindings/spi/fsl,spi.yaml | 73 ++++++++++++++++++++++
 Documentation/devicetree/bindings/spi/fsl-spi.txt  | 62 ------------------
 3 files changed, 137 insertions(+), 62 deletions(-)

diff --git a/Documentation/devicetree/bindings/spi/fsl,espi.yaml b/Documentation/devicetree/bindings/spi/fsl,espi.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..c504b7957dde39086ef7d7a7550d6169cf5ec407
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/fsl,espi.yaml

@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spi/fsl,espi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Freescale eSPI (Enhanced Serial Peripheral Interface) controller
+
+maintainers:
+  - J. Neuschäfer <j.ne@posteo.net>
+
+properties:
+  compatible:
+    const: fsl,mpc8536-espi
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  fsl,espi-num-chipselects:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [ 1, 4 ]
+    description: The number of the chipselect signals.
+
+  fsl,csbef:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 15
+    description: Chip select assertion time in bits before frame starts
+
+  fsl,csaft:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 15
+    description: Chip select negation time in bits after frame ends
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - fsl,espi-num-chipselects
+
+allOf:
+  - $ref: spi-controller.yaml#
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    spi@110000 {
+        compatible = "fsl,mpc8536-espi";
+        reg = <0x110000 0x1000>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+        interrupts = <53 0x2>;
+        interrupt-parent = <&mpic>;