meson: Configure abi-dumper for mixed headers

We split the headers between include/ and src/ dependening on their
purpose and use different include strategies to differentiate. There's
no restriction on the header names, so make sure abi-dumper is aware.

Change-Id: I21a6da776ce8bbf5d5d1e328f44e9cd650406dea
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
diff --git a/src/meson.build b/src/meson.build
index 6400c33..99e79a2 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -64,6 +64,9 @@
                                input: libpldm,
                                output: 'current.dump',
                                command: [ abi_dumper,
+                                          '-mixed-headers',
+                                          '-include-paths',
+                                          meson.project_source_root() / 'src',
                                           '-public-headers',
                                           meson.project_source_root() / 'include',
                                           '-sort',