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

Make all changes to #include statements and build files.
diff --git a/src/hnbap/UDP-Port-Number.c b/src/hnbap/UDP-Port-Number.c
index 647e546..45a75bf 100644
--- a/src/hnbap/UDP-Port-Number.c
+++ b/src/hnbap/UDP-Port-Number.c
@@ -5,7 +5,7 @@
  * 	`asn1c -gen-PER`
  */
 
-#include <osmocom/osmo-iuh/hnbap/UDP-Port-Number.h>
+#include <osmocom/hnbap/UDP-Port-Number.h>
 
 int
 UDP_Port_Number_constraint(asn_TYPE_descriptor_t *td, const void *sptr,