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

Make all changes to #include statements and build files.
diff --git a/src/hnbap/Ipv6Address.c b/src/hnbap/Ipv6Address.c
index f9b7e43..5be471f 100644
--- a/src/hnbap/Ipv6Address.c
+++ b/src/hnbap/Ipv6Address.c
@@ -5,7 +5,7 @@
  * 	`asn1c -gen-PER`
  */
 
-#include <osmocom/osmo-iuh/hnbap/Ipv6Address.h>
+#include <osmocom/hnbap/Ipv6Address.h>
 
 int
 Ipv6Address_constraint(asn_TYPE_descriptor_t *td, const void *sptr,