dt-bindings: Remove PicoXcell bindings

PicoXcell has had nothing but treewide cleanups for at least the last 8
years and no signs of activity. The most recent activity is a yocto vendor
kernel based on v3.0 in 2015.

Cc: linux-crypto@vger.kernel.org
Acked-by: Jamie Iles <jamie@jamieiles.com>
Link: https://lore.kernel.org/r/20201210200315.2965567-5-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/net/macb.txt

@@ -7,8 +7,6 @@ Required properties:
   Use "cdns,sam9x60-macb" for Microchip sam9x60 SoC.
   Use "cdns,np4-macb" for NP4 SoC devices.
   Use "cdns,at32ap7000-macb" for other 10/100 usage or use the generic form: "cdns,macb".
-  Use "cdns,pc302-gem" for Picochip picoXcell pc302 and later devices based on
-  the Cadence GEM, or the generic form: "cdns,gem".
   Use "atmel,sama5d2-gem" for the GEM IP (10/100) available on Atmel sama5d2 SoCs.
   Use "atmel,sama5d3-macb" for the 10/100Mbit IP available on Atmel sama5d3 SoCs.
   Use "atmel,sama5d3-gem" for the Gigabit IP available on Atmel sama5d3 SoCs.

Documentation/devicetree/bindings/timer/snps,dw-apb-timer.yaml

@@ -38,13 +38,6 @@ properties:
 
   clock-frequency: true
 
-  clock-freq:
-    $ref: "/schemas/types.yaml#/definitions/uint32"
-    description: |
-      Has the same meaning as the 'clock-frequency' property - timer clock
-      frequency in HZ, but is defined only for the backwards compatibility
-      with the picoxcell platform.
-
 additionalProperties: false
 
 required: