machine/rp2040: correct issue with spi pin validation

Signed-off-by: deadprogram <ron@hybridgroup.com>

src/machine/machine_rp2040_spi.go

@@ -181,22 +181,24 @@ func (spi SPI) Configure(config SPIConfig) error {
 	var okSDI, okSDO, okSCK bool
 	switch spi.Bus {
 	case rp.SPI0:
-		okSDI = config.SDI == 0 || config.SDI == 4 || config.SDI == 17
+		okSDI = config.SDI == 0 || config.SDI == 4 || config.SDI == 16
 		okSDO = config.SDO == 3 || config.SDO == 7 || config.SDO == 19
 		okSCK = config.SCK == 2 || config.SCK == 6 || config.SCK == 18
 	case rp.SPI1:
-		okSDI = config.SDI == 8 || config.SDI == 12
+		okSDI = config.SDI == 8 || config.SDI == 12 || config.SDI == 28
-		okSDO = config.SDO == 11 || config.SDO == 15
+		okSDO = config.SDO == 11 || config.SDO == 15 || config.SDO == 27
-		okSDO = config.SCK == 10 || config.SCK == 14
+		okSCK = config.SCK == 10 || config.SCK == 14 || config.SCK == 26
 	}
 
-	if !okSDI {
+	switch {
+	case !okSDI:
 		return errSPIInvalidSDI
-	} else if !okSDO {
+	case !okSDO:
 		return errSPIInvalidSDO
-	} else if !okSCK {
+	case !okSCK:
 		return errSPIInvalidSCK
 	}
+
 	if config.DataBits < 4 || config.DataBits > 16 {
 		config.DataBits = 8
 	}