Remove osmo-iuh subdir level from include/ (2/2)

Make all changes to #include statements and build files.
diff --git a/src/rua/RUA_CN-DomainIndicator.c b/src/rua/RUA_CN-DomainIndicator.c
index 4a8812c..e7e137e 100644
--- a/src/rua/RUA_CN-DomainIndicator.c
+++ b/src/rua/RUA_CN-DomainIndicator.c
@@ -4,7 +4,7 @@
  * 	found in "../../asn1/rua/RUA-IEs.asn"
  */
 
-#include <osmocom/osmo-iuh/rua/RUA_CN-DomainIndicator.h>
+#include <osmocom/rua/RUA_CN-DomainIndicator.h>
 
 int
 RUA_CN_DomainIndicator_constraint(asn_TYPE_descriptor_t *td, const void *sptr,