[yellowstone] Add a way to retrieve to denali client from yellowstone

sys/denali/include/denali/denali_client.h

@@ -16,3 +16,22 @@ class DenaliClient {
  private:
   glcr::UniquePtr<EndpointClient> endpoint_;
 };
+
+class ScopedDenaliClient : protected DenaliClient {
+ public:
+  ScopedDenaliClient(glcr::UniquePtr<EndpointClient> endpoint,
+                     uint64_t device_id, uint64_t lba_offset)
+      : DenaliClient(glcr::Move(endpoint)),
+        device_id_(device_id),
+        lba_offset_(lba_offset) {}
+
+  glcr::ErrorOr<MappedMemoryRegion> ReadSectors(uint64_t lba,
+                                                uint64_t num_sectors) {
+    return DenaliClient::ReadSectors(device_id_, lba_offset_ + lba,
+                                     num_sectors);
+  }
+
+ private:
+  uint64_t device_id_;
+  uint64_t lba_offset_;
+};