Revert "auxdisplay: hd44780: Convert to platform remove callback returning void"

This reverts commit 959b07fb which is
commit 9ea02f7c upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I2a34cd4b6141cea3d94338885b1f3919c143e8dd
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>