meson: Define include_directories in dependencies for static libraries

This way the headers are found automatically via the dependency objects.

Change-Id: I740b331cd134497663dbd21565ea918c861f9901
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
diff --git a/src/meson.build b/src/meson.build
index f619572..64d156d 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -20,6 +20,7 @@
 )
 
 thresholds_dep = declare_dependency(
+    include_directories: ['.'],
     link_with: [thresholds_a],
     dependencies: default_deps,
 )
@@ -35,6 +36,7 @@
 )
 
 utils_dep = declare_dependency(
+    include_directories: ['.'],
     link_with: [utils_a],
     dependencies: [sdbusplus],
 )
@@ -48,6 +50,7 @@
 )
 
 devicemgmt_dep = declare_dependency(
+    include_directories: ['.'],
     link_with: [devicemgmt_a],
     dependencies: default_deps,
 )
@@ -59,6 +62,7 @@
 )
 
 pwmsensor_dep = declare_dependency(
+    include_directories: ['.'],
     link_with: [pwmsensor_a],
     dependencies: [default_deps, thresholds_dep],
 )