Revert "Input: elantech - enable SMBus on new (2018+) systems"

Revert "Input: elantech - enable SMBus on new (2018+) systems"

This reverts commit 0eb106b1d3f6d7b4133b9ed853e0d0a12aba8f85.

Apparently use dmi_get_bios_year() as manufacturing date isn't accurate
and this breaks older laptops with new BIOS update.

So let's revert this patch.

There are still new HP laptops still need to use SMBus to support all
features, but it'll be enabled via a whitelist.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20191001070845.9720-1-kai.heng.feng@canonical.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>