Input: elantech - force relative mode on a certain module

One of Elan modules with sample version is 0x74 and hw_version is 0x03 has
a bug in absolute mode implementation, so let it run in default PS/2
relative mode.

Signed-off-by: KT Liao <kt.liao@emc.com.tw>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>