variants: Sensecap Solar: Use DC/DC regulator

The schematic shows the LC circuit for the internal DC/DC regulator
to be available. Enable it to save power.

Signed-off-by: Frieder Schrempf <frieder@fris.de>

variants/sensecap_solar/SenseCapSolarBoard.h

@@ -4,7 +4,7 @@
 #include <Arduino.h>
 #include <helpers/NRF52Board.h>
 
-class SenseCapSolarBoard : public NRF52BoardOTA {
+class SenseCapSolarBoard : public NRF52BoardDCDC, public NRF52BoardOTA {
 public:
   SenseCapSolarBoard() : NRF52BoardOTA("SENSECAP_SOLAR_OTA") {}
   void begin();