mips: configs: ci20: Enable DRM_DW_HDMI

Commit 4fc8cb47fcfd ("drm/display: Move HDMI helpers into display-helper
module") turned the DRM_DW_HDMI dependency of DRM_INGENIC_DW_HDMI into a
depends on which ended up disabling the drivers in the defconfig. Make
sure it's still enabled.

Fixes: 4fc8cb47fcfd ("drm/display: Move HDMI helpers into display-helper module")
Reported-by: Mark Brown <[e-mail]>
Reported-by: Alexander Stein <[e-mail]>
Signed-off-by: Maxime Ripard <[e-mail]>
Signed-off-by: Thomas Bogendoerfer <[e-mail]>

arch/mips/configs/ci20_defconfig

···
 CONFIG_MEDIA_SUPPORT=m
 CONFIG_DRM=m
 CONFIG_DRM_DISPLAY_CONNECTOR=m
+CONFIG_DRM_DW_HDMI=m
 CONFIG_DRM_INGENIC=m
 CONFIG_DRM_INGENIC_DW_HDMI=m
 CONFIG_FB=y