atmel_mxt_ts: [HACK DV20] load correct cfg file

atmel_mxt_ts: [HACK DV20] load correct cfg file

BZ: 31105

There are 3 touch panels used on medfield tablet, we need to load correct
cfg file to make touch work.
dv1.0       mxt1386         0x4c maxtouch.cfg
dv2.0       mxt1386_wintek  0x4c maxtouch_wintek.cfg
dv2.0       mxt1386_hanns   0x4d maxtouch_hanns.cfg

currently we use dev name to differentiate dv10 or dv20 panel, while uses
i2c slave address to differentiate two dv20 panels.

This hack can be removed once firmware can runtime detect panel type.

Change-Id: Ie1ba8793f2e311322b1b0f98772de5b1b6d4de7a
Signed-off-by: Hong Liu <hong.liu@intel.com>
Reviewed-on: http://android.intel.com:8080/43071
Reviewed-by: Wood, Brian J <brian.j.wood@intel.com>
Reviewed-by: Lebouc, Christophe <christophe.lebouc@intel.com>
Tested-by: Lebouc, Christophe <christophe.lebouc@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>