clk: qcom: dispcc-qcm2290: Remove inexistent DSI1PHY clk

There's only one DSI PHY on this SoC. Remove the ghost entry for the
clock produced by a secondary one.

Fixes: cc517ea3

 ("clk: qcom: Add display clock controller driver for QCM2290")
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230412-topic-qcm_dispcc-v1-2-bf2989a75ae4@linaro.org