Add SPI NOR Flash driver, WIP.

src/drivers/SpiNorFlash.h

@@ -0,0 +1,28 @@
+#pragma once
+#include <cstddef>
+
+namespace Pinetime {
+  namespace Drivers {
+    class Spi;
+    class SpiNorFlash {
+      public:
+        explicit SpiNorFlash(Spi& spi);
+        SpiNorFlash(const SpiNorFlash&) = delete;
+        SpiNorFlash& operator=(const SpiNorFlash&) = delete;
+        SpiNorFlash(SpiNorFlash&&) = delete;
+        SpiNorFlash& operator=(SpiNorFlash&&) = delete;
+
+        void Init();
+        void Uninit();
+
+
+        void Sleep();
+        void Wakeup();
+      private:
+        Spi& spi;
+
+    };
+  }
+}
+
+