atmel_mxt_ts.c: move to current github.com/atmel-maxtouch

This is driver from commit ID: 72c03333f35f7eddd707680d8e5de3527b5ef674.

Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
[eugen.hristev@microchip.com: adapted original patch to 4.14]
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>

Author: noglitch