[Silabs] removed extern from AirQualitySensor.cpp (project-chip#37951)

* removed externs from airqualitysnsors.cpp

* Restyled by clang-format

---------

Co-authored-by: Restyled.io <commits@restyled.io>

Author: Sarthak-Shaha

examples/platform/silabs/sensors/AirQuality/AirQualitySensor.cpp

@@ -22,12 +22,8 @@
 #include <platform/CHIPDeviceLayer.h>
 
 #ifdef USE_SPARKFUN_AIR_QUALITY_SENSOR
-#ifdef __cplusplus
-extern "C" {
-#endif
-#include <sparkfun_sgp40.h>
-}
 #include "sl_i2cspm_instances.h"
+#include <sparkfun_sgp40.h>
 #endif // USE_SPARKFUN_AIR_QUALITY_SENSOR
 
 namespace {