e1_input: Use osmo_use_count in e1inp_line

osmo_use_count is available since libosmocore 1.1.0 release, so bump
required libosmocore version in autotools and packages.

struct e1inp_line field refcnt is kept in order to keep ABI
compatibility accessing struct fields. The new use_count is added at the
end. Size of struct changing is fine since it is allocated through
an API and a pointer should be used by clients.

e1inp_line_clone API is changed but it's not used by anyone outside
libosmo-abis, so it's fine.

Related: OS#4624
Change-Id: I0658b2e9c452598025cc0f1d0b060076171767cc
diff --git a/debian/control b/debian/control
index b9e2078..7039bfe 100644
--- a/debian/control
+++ b/debian/control
@@ -11,7 +11,7 @@
                dh-autoreconf,
                libdpkg-perl,
                git,
-               libosmocore-dev (>= 1.0.0),
+               libosmocore-dev (>= 1.1.0),
                pkg-config,
                libortp-dev
 Standards-Version: 3.9.7