Input: elantech - fix protocol errors for some trackpoints in SMBus mode

Input: elantech - fix protocol errors for some trackpoints in SMBus mode

commit e4c9062717feda88900b566463228d1c4910af6d upstream.

There are some version of Elan trackpads that send incorrect data when
in SMbus mode, unless they are switched to use 0x5f reports instead of
standard 0x5e. This patch implements querying device to retrieve chips
identifying data, and switching it, when needed to the alternative
report.

Signed-off-by: Jingle Wu <jingle.wu@emc.com.tw>
Link: https://lore.kernel.org/r/20201211071531.32413-1-jingle.wu@emc.com.tw
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>