dt-bindings: mfd: ocelot: Remove unnecessary driver wording

Initially there was unnecessary verbage around "this driver" in the
documentation. It was unnecessary. Remove self references about it being a
"driver" documentation and replace it with a more detailed description
about external interfaces that are supported.
Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Suggested-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20221025050355.3979380-3-colin.foster@in-advantage.com

Documentation/devicetree/bindings/mfd/mscc,ocelot.yaml

@@ -12,7 +12,8 @@ maintainers:
 description: |
   The Ocelot ethernet switch family contains chips that have an internal CPU
   (VSC7513, VSC7514) and chips that don't (VSC7511, VSC7512). All switches have
-  the option to be controlled externally, which is the purpose of this driver.
+  the option to be controlled externally via external interfaces like SPI or
+  PCIe.
 
   The switch family is a multi-port networking switch that supports many
   interfaces. Additionally, the device can perform pin control, MDIO buses, and