sdcard: add support for fatfs

examples/sdcard/console/main.go

@@ -10,6 +10,9 @@ import (
 
 var (
 	spi    machine.SPI
+	sckPin machine.Pin
+	sdoPin machine.Pin
+	sdiPin machine.Pin
 	csPin  machine.Pin
 	ledPin machine.Pin
 )
@@ -21,7 +24,7 @@ func main() {
 	led := ledPin
 	led.Configure(machine.PinConfig{Mode: machine.PinOutput})
 
-	sd := sdcard.New(spi, csPin)
+	sd := sdcard.New(spi, sckPin, sdoPin, sdiPin, csPin)
 	err := sd.Configure()
 	if err != nil {
 		fmt.Printf("%s\r\n", err.Error())