dt-bindings: ethernet: eswin: fix yaml schema issues

dt-bindings: ethernet: eswin: fix yaml schema issues

eswin,hsp-sp-csr attribute is one phandle with multiple arguments,
so the syntax should be in the form of:
 items:
   - items:
       - description: ...
       - description: ...
       - description: ...
       - description: ...

To align with the description of the 'eswin-sp-csr'
attribute in the mmc,usb modules, the description
of the 'eswin,hsp-sp-csr' attribute has been modified.

Fixes: 888bd0eca93c ("dt-bindings: ethernet: eswin: Document for EIC7700 SoC")
Reported-by: Rob Herring (Arm) <robh@kernel.org>
Closes: https://lore.kernel.org/all/176096011380.22917.1988679321096076522.robh@kernel.org/
Signed-off-by: Shangjuan Wei <weishangjuan@eswincomputing.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20251104073305.299-1-weishangjuan@eswincomputing.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>