Add 'irremote' package as a basic infra-red driver

Currently contains an IR Receiver device only.
An IR Sender device will be added shortly

Supports receiving only NEC (extended address) protocol including repeat codes so far

examples/irremote/main.go

@@ -0,0 +1,58 @@
+package main
+
+import (
+	"machine"
+	"time"
+
+	"tinygo.org/x/drivers/irremote"
+)
+
+var irCmdButtons = map[uint16]string{
+	0xA2: "POWER",
+	0xE2: "FUNC/STOP",
+	0x62: "VOL+",
+	0x22: "FAST BACK",
+	0x02: "PAUSE",
+	0xC2: "FAST FORWARD",
+	0xE0: "DOWN",
+	0xA8: "VOL-",
+	0x90: "UP",
+	0x98: "EQ",
+	0xB0: "ST/REPT",
+	0x68: "0",
+	0x30: "1",
+	0x18: "2",
+	0x7A: "3",
+	0x10: "4",
+	0x38: "5",
+	0x5A: "6",
+	0x42: "7",
+	0x4A: "8",
+	0x52: "9",
+}
+
+var (
+	pinIRIn = machine.GP26
+	ir      irremote.ReceiverDevice
+)
+
+func setupPins() {
+	ir = irremote.NewReceiver(pinIRIn)
+	ir.Configure()
+}
+
+func irCallback(data irremote.Data) {
+	msg := "Command: " + irCmdButtons[data.Command]
+	if data.Flags&irremote.DataFlagIsRepeat != 0 {
+		msg = msg + " (REPEAT)"
+	}
+	println(msg)
+}
+
+func main() {
+	setupPins()
+	ir.SetCommandHandler(irCallback)
+	for {
+		time.Sleep(time.Millisecond * 10)
+	}
+}