drm/display: Drop obsolete dependency on COMPILE_TEST

drm/display: Drop obsolete dependency on COMPILE_TEST

Since commit 0166dc11be91 ("of: make CONFIG_OF user selectable"), it
is possible to test-build any driver which depends on OF on any
architecture by explicitly selecting OF. Therefore depending on
COMPILE_TEST as an alternative is no longer needed.

To avoid reintroducing the randconfig bug originally fixed by commit
876271118aa4 ("drm/display: Fix build error without CONFIG_OF"),
DRM_MSM which selects DRM_DISPLAY_DP_HELPER must explicitly depend
on OF. This is consistent with what all other DRM drivers are doing.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Acked-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241015134606.5b87093e@endymion.delvare
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>