Revert "drm/msm/disp/dpu: Use proper define for drm_encoder_init() 'encoder_type'"

This reverts commit 721b54a6.

This is a preparation change for merging LTS tag v4.19.3 into
msm-kona branch.

DPU will not be used in 4.19 downstream display driver code.
Separate patches are submitted to introduce the downstream
version of the display driver.

Change-Id: I823da2a2ac319c192cb6289596437d1244c5b028
Signed-off-by: Blagovest Kolenichev <bkolenichev@codeaurora.org>