nrf,sam,rp2040: add machine.HardwareID function

src/machine/deviceid.go

@@ -0,0 +1,17 @@
+//go:build rp2040 || nrf || sam
+
+package machine
+
+// DeviceID returns an identifier that is unique within
+// a particular chipset.
+//
+// The identity is one burnt into the MCU itself, or the
+// flash chip at time of manufacture.
+//
+// It's possible that two different vendors may allocate
+// the same DeviceID, so callers should take this into
+// account if needing to generate a globally unique id.
+//
+// The length of the hardware ID is vendor-specific, but
+// 8 bytes (64 bits) and 16 bytes (128 bits) are common.
+var _ = (func() []byte)(DeviceID)