Input: iqs5xx - simplify axis setup logic

Input: iqs5xx - simplify axis setup logic

The present implementation manipulates axis swap and inversion fields
in the device to more or less duplicate what touchscreen_report_pos()
does. The resulting logic is convoluted and difficult to follow.

Instead report the maximum X and Y coordinates in earnest as they are
read from the device, then let touchscreen_parse_properties() fix the
axes up as necessary. Finally, use touchscreen_report_pos() to report
the transformed coordinates.

Last but not least, the maximum X and Y coordinates are not functions
of the number of rows/columns that comprise the touch surface. Either
coordinate is simply limited to 1 below what is reported for absolute
X or Y coordinates when no fingers are present (0xFFFF).

Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/1611002626-5889-7-git-send-email-jeff@labundy.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>