Add SPI NOR Flash driver, WIP.

src/drivers/Spi.h

@@ -0,0 +1,33 @@
+#pragma once
+#include <FreeRTOS.h>
+#include <cstdint>
+#include <cstddef>
+#include <array>
+#include <atomic>
+#include <task.h>
+
+#include "BufferProvider.h"
+#include "SpiMaster.h"
+
+namespace Pinetime {
+  namespace Drivers {
+    class Spi {
+      public:
+        Spi(SpiMaster& spiMaster, uint8_t pinCsn);
+        Spi(const Spi&) = delete;
+        Spi& operator=(const Spi&) = delete;
+        Spi(Spi&&) = delete;
+        Spi& operator=(Spi&&) = delete;
+
+        bool Init();
+        bool Write(const uint8_t* data, size_t size);
+        bool Read(uint8_t* data, size_t size);
+        void Sleep();
+        void Wakeup();
+
+      private:
+        SpiMaster& spiMaster;
+        uint8_t pinCsn;
+    };
+  }
+}