Revert "drm/connector: Add support for out-of-band hotplug notification (v3)"

This reverts commit 2ea6a14e which is
commit 72ad4968 upstream.

It breaks the android ABI and if this is needed in the future, can be
brought back in an abi-safe way.

Bug: 161946584
Change-Id: I168048886443f3d5e653a70ceea1affda068894f
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>