Nano33 IoT: default SPI should be D13/D11/D12 instead of A2/A3/A6 (#781)

* Nano33 IoT: default SPI should be D13/D11/D12 instead of A2/A3/A6

src/machine/board_arduino_nano33.go

@@ -66,9 +66,9 @@ const (
 
 // SPI pins
 const (
-	SPI0_SCK_PIN  Pin = A2 // SCK: SERCOM0/PAD[3]
+	SPI0_SCK_PIN  Pin = D13 // SCK: SERCOM1/PAD[1]
-	SPI0_MOSI_PIN Pin = A3 // MOSI: SERCOM0/PAD[2]
+	SPI0_MOSI_PIN Pin = D11 // MOSI: SERCOM1/PAD[0]
-	SPI0_MISO_PIN Pin = A6 // MISO: SERCOM0/PAD[1]
+	SPI0_MISO_PIN Pin = D12 // MISO: SERCOM1/PAD[3]
 )
 
 // NINA-W102 Pins

src/machine/board_arduino_nano33_baremetal.go

@@ -45,8 +45,8 @@ var (
 // SPI on the Arduino Nano 33.
 var (
 	SPI0 = SPI{
-		Bus:    sam.SERCOM0_SPI,
+		Bus:    sam.SERCOM1_SPI,
-		SERCOM: 0,
+		SERCOM: 1,
 	}
 )