drivers: Add Atmel SAM counter (TC) Driver

Add basic counter driver based on Timer Counter (TC) module for Atmel
SAM family.

Remarks:
- The driver is not thread safe.
- The driver does not implement guard periods.
- The driver does not guarantee that short relative alarm will trigger
  the interrupt immediately and not after the full cycle / counter
  overflow.

Tested on Atmel SMART SAM E70 Xplained board

Origin: Original

Signed-off-by: Piotr Mienkowski <piotr.mienkowski@gmail.com>