sdcard: add support for fatfs

examples/sdcard/console/pygamer.go

@@ -0,0 +1,17 @@
+// +build pygamer
+
+package main
+
+import (
+	"machine"
+)
+
+func init() {
+	spi = machine.SPI0
+	sckPin = machine.SPI0_SCK_PIN
+	sdoPin = machine.SPI0_SDO_PIN
+	sdiPin = machine.SPI0_SDI_PIN
+	csPin = machine.D4
+
+	ledPin = machine.LED
+}