Input: elan_i2c - fix detecting IAP version on older controllers

Older controllers in bootloader mode need a different command to retrieve
the IAP version.

Signed-off-by: Jingle Wu <jingle.wu@emc.com.tw>
Link: https://lore.kernel.org/r/20200714105641.15151-1-jingle.wu@emc.com.tw


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>