lvm2: update our portability patch.

srcpkgs/lvm2/patches/portability.patch

@@ -47,15 +47,3 @@ Portability fixes:
  #include <errno.h>
  #include <pthread.h>
 
---- libdm/libdm-timestamp.c.orig	2015-08-10 01:49:59.000000000 +0200
-+++ libdm/libdm-timestamp.c	2015-08-11 08:20:26.324155251 +0200
-@@ -34,7 +34,9 @@
- #ifdef HAVE_REALTIME
- 
- #include <time.h>
-+#ifdef __GLIBC__
- #include <bits/time.h>
-+#endif
- 
- struct dm_timestamp {
- 	struct timespec t;