drivers: input: pinnacle: add driver for trackpad

The initial version of an input driver for Cirque Pinnacle ASIC supports:
 * Setting sensitivity
 * Choosing between relative and absolute modes
  * Relative mode
   * Primary tap
   * Swapping X and Y
  * Absolute mode
   * Setting number of idle packets
   * Clipping coordinates outside of active range
   * Scaling coordinates
   * Inverting X and Y coordinates

Signed-off-by: Ilia Kharin <akscram@gmail.com>