dt-bindings: display: msm: Add optional resets

dt-bindings: display: msm: Add optional resets

Add an optional reference to the MDSS_CORE reset, which when specified
can be used by the implementation to reset the hardware blocks.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/482794/
Link: https://lore.kernel.org/r/20220421041550.643964-1-bjorn.andersson@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>