Require newer version of libosmocore to avoid build failure

Older commit started using osmo_timerd_* APIs which are only available
starting libosmocore 0.12.0, but configure.ac still states 0.11.0 is
accepted, which is incorrect.

Fixes: 4456b6f132437a95833e3a3d3353836331b9c8a0
Change-Id: I71743b8a10edb10af51ad8e9289c53e432199b97
diff --git a/configure.ac b/configure.ac
index f2664ed..fa9cf8d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -75,9 +75,9 @@
 AC_HEADER_TIME
 AC_C_BIGENDIAN
 
-PKG_CHECK_MODULES(LIBOSMOCORE, libosmocore >= 0.11.0)
-PKG_CHECK_MODULES(LIBOSMOVTY, libosmovty >= 0.11.0)
-PKG_CHECK_MODULES(LIBOSMOCTRL, libosmoctrl >= 0.11.0)
+PKG_CHECK_MODULES(LIBOSMOCORE, libosmocore >= 0.12.0)
+PKG_CHECK_MODULES(LIBOSMOVTY, libosmovty >= 0.12.0)
+PKG_CHECK_MODULES(LIBOSMOCTRL, libosmoctrl >= 0.12.0)
 
 AC_ARG_ENABLE(sanitize,
 	[AS_HELP_STRING(