Refactor of bmcImages

bmcImages were in image_verify.hpp but it is used not only in image
verification, but elsewhere.

Move it into a more generic header file, images.hpp, so it makes more
clear that users of bmcImages include images.hpp instead of
image_verify.hpp

Tested: Verify the code pass the build.

Change-Id: If9adf315eee9047d9d08ab93ed7c0ff3c97f7a1e
Signed-off-by: Lei YU <mine260309@gmail.com>
diff --git a/activation.hpp b/activation.hpp
index 7f0120f..654d21f 100644
--- a/activation.hpp
+++ b/activation.hpp
@@ -199,7 +199,7 @@
  *  @details A concrete implementation for
  *  xyz.openbmc_project.Software.Activation DBus API.
  */
-class Activation : public ActivationInherit, Flash
+class Activation : public ActivationInherit, public Flash
 {
   public:
     /** @brief Constructs Activation Software Manager