disp: msm: dp: use sde_drm.h shared header from techpack path

Update sde_drm.h header to use the display techpack path for
kernel-5.4.

Change-Id: I2b7dcbbde8128eece7a2a8a652f9f7c427b38110
Signed-off-by: Tatenda Chipeperekwa <tatendac@codeaurora.org>