lpc_aspeed: implement copyFrom

Implement copyFrom as effectively a memcpy from the mapped region into a
vector.

Change-Id: I7b629fc0aef69c65373a74ac086b8a038f2da53e
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/lpc_aspeed.cpp b/lpc_aspeed.cpp
index f1caaa5..9d09858 100644
--- a/lpc_aspeed.cpp
+++ b/lpc_aspeed.cpp
@@ -151,8 +151,7 @@
         }
     }
 
-    /* TODO: Implement this. */
-    return {};
+    return std::vector<std::uint8_t>(mappedRegion, mappedRegion + length);
 }
 
 } // namespace blobs