dt-bindings: display: lt8912b: Drop redundant endpoint properties

dt-bindings: display: lt8912b: Drop redundant endpoint properties

The "endpoint" node references video-interfaces.yaml schema with
"unevaluatedProperties: false" which means that all properties from
referenced schema apply.  Listing some of them with ": true" is simply
redundant and does not make this code easier to read.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260316134606.57070-2-krzysztof.kozlowski@oss.qualcomm.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>