[SPI] Avoid unnecessarily reconfiguring the bus

src/shared/drivers/spi/SPIBus.h

@@ -168,14 +168,19 @@ public:
 private:
     SPI spi;
     SPIBusConfig config{};
+    bool firstConfigApplied = false;
 };
 
 inline SPIBus::SPIBus(SPIType* spi) : spi(spi) {}
 
 inline void SPIBus::configure(SPIBusConfig newConfig)
+{
+    // Do not reconfigure if already in the correct configuration.
+    if (!firstConfigApplied || newConfig != config)
     {
         // Save the new configuration
         config             = newConfig;
+        firstConfigApplied = true;
 
         // Wait until the peripheral is done before changing configuration
         spi.waitPeripheral();
@@ -200,6 +205,7 @@ inline void SPIBus::configure(SPIBusConfig newConfig)
         // Enable the peripheral
         spi.enable();
     }
+}
 
 inline void SPIBus::select(GpioType& cs)
 {