drm/msm/edp: drop old eDP support

MSM DRM driver has support for eDP block present on MSM 8x74/8x84 SoC
families. However since addition back in 2015 this driver received only
generic fixes. No actual devices with these SoCs supported upstream (or
by the community) seem to support eDP panels. Judging from downstream
kernels the eDP was present only on MSM8974 LIQUID or on APQ8084 CDP.
Remove this driver.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20211001165011.441945-3-dmitry.baryshkov@linaro.org


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
[rob: Rebased on "drm: msm: fix building without CONFIG_COMMON_CLK"]
Signed-off-by: Rob Clark <robdclark@chromium.org>