drivers: hwinfo: add driver support for Atmel SAM0 device ID

Add driver support for Atmel SAM0 device ID, which is 16-bytes long.
The device ID can simply be read from memory at a known location, but
the location is only described in the data sheet, not in ASF.

For SAMD2x it's 0x0080A00C, 0x0080A040, 0x0080A044 & 0x0080A048.
For SAMD5x it's 0x008061FC, 0x00806010, 0x00806014 & 0x00806018.

This adds a new property to the device tree to define the device ID
registers for this SoC family.

Signed-off-by: Benjamin Valentin <benjamin.valentin@ml-pa.com>