drm: bridge: adv7511: Remove DRM_I2C_ADV7533 Kconfig

This commit remove DRM_I2C_ADV7533 resulting a simpler driver and less
choices in Kconfig.

Signed-off-by: Bogdan Togorean <bogdan.togorean@analog.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200121082719.27972-2-bogdan.togorean@analog.com