Input: tps6507x-ts - convert to polled input device infrastructure

There is no need to roll our own polling scheme when we already have
one implemented by the core.

Tested-by: Manish Badarkhe <badarkhe.manish@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

input: Touchscreen driver for TPS6507x

Add touch screen input driver for TPS6507x family of multi-function
chips. Uses the TPS6507x MFD driver. No interrupt support due to
testing limitations of current hardware.

Signed-off-by: Todd Fischer <todd.fischer@ridgerun.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

mfd: Add TPS6507x support

TPS6507x are multi function (PM, touchscreen) chipsets from TI.
This commit also changes the corresponding regulator driver from being
standalone to an MFD subdevice.

Signed-off-by: Todd Fischer <todd.fischer@ridgerun.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

mfd: Add tps6507x board data structure

Add mfd structure which refrences sub-driver initialization data. For example,
for a giving hardware implementation, the voltage regulator sub-driver
initialization data provides the mapping betten a voltage regulator and what
the output voltage is being used for.

Signed-off-by: Todd Fischer <todd.fischer@ridgerun.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

mfd: Move TPS6507x register definition to header file.

Other sub-drivers for the TPS6507x chip will need to use register
definition so move it out of the source file and into a header file.

Signed-off-by: Todd Fischer <todd.fischer@ridgerun.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>