Input: atmel_mxt_ts - improve error handling in initialise functions

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
Input: atmel_mxt_ts - Improve device tree parsing for earlier kernels

of_property_read_u32_index() was only introduced in v3.10. Using the array
operation is simpler anyway.

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
Input: atmel_mxt_ts - add cfg name and input name to device tree

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
Input: atmel_mxt_ts - reorder mxt_free_object_table to improve robustness

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
Input: atmel_mxt_ts - move functions in file to improve code layout

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
Input: atmel_mxt_ts - check gpio validity in mxt_probe_regulators

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
Input: atmel_mxt_ts - support config checksum attribute in sysfs

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
Input: atmel_mxt_ts - allocate pdata using devm_kzalloc

By using this function instead, there is no necessity to free on remove or
probe failure, since it is handled for us. This also fixes an failure when
kfree() is called on memory allocated using devm_kzalloc() in the DT parse
function.

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>