Revert "input: touchscreen: refactoring dt2w code"

This reverts commit 0c2ee43431a3a049dc0665fe81242d2afd8c799c.

Caused more troubles than it solved. So i am reverting this and
hope no one will ever ask why its not guideline conform.

Signed-off-by: Blechd0se <alex.christ@hotmail.de>
dt2w: improve accuracy of single touch detection

Signed-off-by: Blechd0se <alex.christ@hotmail.de>
proximity: power off the sensor if dt2w/s2w is disabled

Signed-off-by: Blechd0se <alex.christ@hotmail.de>
input: declare variables dependant on s2w/dt2w when the features are disabled

Signed-off-by: Blechd0se <alex.christ@hotmail.de>
input: touchscreen: code guideline fixes

Just the usual fixes, nothing to fancy.

Signed-off-by: Blechd0se <alex.christ@hotmail.de>