ARM: dts: qcom: apq8064: disable DSI and DSI PHY by default

Disable DSI and DSI PHY devices by default. The only actual user,
Nexus 7, already contains `status = "okay"` property in the respective
devices nodes.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220706145412.1566011-5-dmitry.baryshkov@linaro.org