Input: drv260x - add TI drv260x haptics driver

Add the TI drv260x haptics/vibrator driver.  This device uses the input
force feedback to produce a wave form to driver an ERM or LRA actuator
device.

The initial driver supports the devices real time playback mode.  But the
device has additional wave patterns in ROM. This functionality will be
added in future patchsets.

Product data sheet is located here: http://www.ti.com/product/drv2605



Signed-off-by: Dan Murphy <dmurphy@ti.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>