Revert "drm/display: Select DRM_KMS_HELPER for DP helpers"

This reverts commit 7fa678cc, as the
commit it fixes will be reverted, too.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patchwork.freedesktop.org/patch/msgid/17b6a2c5f3250a7d02ee1b517182ca6fd9baa45a.1713780345.git.geert+renesas@glider.be


Signed-off-by: Maxime Ripard <mripard@kernel.org>