arm64: dts: qcom: sm8350-hdk: correct LT9611 pin function

SM8350 pin controller does not have "normal" pin function, so use
"gpio".

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Fixes: d96d8f91 ("arm64: dts: qcom: sm8350-hdk: Enable lt9611uxc dsi-hdmi bridge")
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230201154321.276419-2-krzysztof.kozlowski@linaro.org