Power optimization - Improve SPI sleep mode

Ensure that all pins are set to their default configuration during sleep mode.
Disable the workaround for FTPAN58 (SPI freezes when transfering a single byte) at the end of the transfer. This disables the resources needed for the workaround.
Those changes reduce the power usage by 430-490µA.

src/drivers/SpiMaster.cpp

@@ -204,6 +204,9 @@ bool SpiMaster::Write(uint8_t pinCsn, const uint8_t* data, size_t size) {
       ;
     nrf_gpio_pin_set(this->pinCsn);
     currentBufferAddr = 0;
+
+    DisableWorkaroundForFtpan58(spiBaseAddress, 0, 0);
+
     xSemaphoreGive(mutex);
   }