Align source structure away from anti-patterns

The anti-patterns document comments on source structure, specifically on
placing internal headers in a parallel subtree[1]. entity-manager is an
example of violating this anti-pattern, so fix it.

[1]: https://github.com/openbmc/docs/blob/master/anti-patterns.md#placing-internal-headers-in-a-parallel-subtree

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Change-Id: I6c9739d1d532ea670e5ceb30044017c38e49eed3
diff --git a/meson.build b/meson.build
index f590b79..139b43c 100644
--- a/meson.build
+++ b/meson.build
@@ -227,8 +227,7 @@
                 sdbusplus,
                 valijson,
             ],
-            implicit_include_directories: false,
-            include_directories: 'include',
+            include_directories: 'src',
         )
     )
 
@@ -244,8 +243,7 @@
                 boost,
                 gtest,
             ],
-            implicit_include_directories: false,
-            include_directories: 'include',
+            include_directories: 'src',
         )
     )
 
@@ -260,8 +258,7 @@
                 gtest,
                 gmock,
             ],
-            implicit_include_directories: false,
-            include_directories: 'include',
+            include_directories: 'src',
         )
     )
 endif
diff --git a/include/devices.hpp b/src/devices.hpp
similarity index 100%
rename from include/devices.hpp
rename to src/devices.hpp
diff --git a/include/entity_manager.hpp b/src/entity_manager.hpp
similarity index 100%
rename from include/entity_manager.hpp
rename to src/entity_manager.hpp
diff --git a/include/expression.hpp b/src/expression.hpp
similarity index 100%
rename from include/expression.hpp
rename to src/expression.hpp
diff --git a/include/fru_reader.hpp b/src/fru_reader.hpp
similarity index 100%
rename from include/fru_reader.hpp
rename to src/fru_reader.hpp
diff --git a/include/fru_utils.hpp b/src/fru_utils.hpp
similarity index 100%
rename from include/fru_utils.hpp
rename to src/fru_utils.hpp
diff --git a/src/meson.build b/src/meson.build
index 0ada42d..a7205ac 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -17,8 +17,6 @@
         sdbusplus,
         valijson,
     ],
-    implicit_include_directories: false,
-    include_directories: '../include',
     install: true,
 )
 
@@ -43,8 +41,6 @@
             threads,
             valijson,
         ],
-        implicit_include_directories: false,
-        include_directories: '../include',
         install: true,
     )
 endif
diff --git a/include/overlay.hpp b/src/overlay.hpp
similarity index 100%
rename from include/overlay.hpp
rename to src/overlay.hpp
diff --git a/include/topology.hpp b/src/topology.hpp
similarity index 100%
rename from include/topology.hpp
rename to src/topology.hpp
diff --git a/include/utils.hpp b/src/utils.hpp
similarity index 100%
rename from include/utils.hpp
rename to src/utils.hpp
diff --git a/include/variant_visitors.hpp b/src/variant_visitors.hpp
similarity index 100%
rename from include/variant_visitors.hpp
rename to src/variant_visitors.hpp