overlays: i2c-sensor: Fix sgp30 alphabetic order

This a purely cosmetic change to move the sgp30 option in the i2c-sensor
README to be in a more logical place.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

Author: pelwell

arch/arm/boot/dts/overlays/README

@@ -2620,6 +2620,9 @@ Params: addr                    Set the address for the AD799X, ADS7828,
 
         scd4x                   Select the Sensirion SCD40/41 CO2 sensors.
 
+        sgp30                   Select the Sensirion SGP30 VOC sensor.
+                                Fixed address 0x58.
+
         sht3x                   Select the Sensirion SHT3x temperature and
                                 humidity sensors. Valid addresses 0x44-0x45,
                                 default 0x44
@@ -2637,8 +2640,6 @@ Params: addr                    Set the address for the AD799X, ADS7828,
         sps30                   Select the Sensirion SPS30 particulate matter
                                 sensor. Fixed address 0x69.
 
-        sgp30                   Select the Sensirion SGP30 VOC sensor.
-                                Fixed address 0x58.
 
         tcs3472                 Select the AMS TAOS TCS3472 family of RGBW light
                                 sensors.