libosmo-netif: Add explicit dependency lksctp-tools

Since libosmo-netif.git d1b1ff77a6bc2f70366c5d2f5079c70f5eae52a0, use of
libsctp is enabled by default and explicitly required.

Change-Id: Ib53557f21cad86300738f43b247df1e17166c46f
diff --git a/recipes-osmocom/libosmo-netif/libosmo-netif.inc b/recipes-osmocom/libosmo-netif/libosmo-netif.inc
index a353be6..0a51dfc 100644
--- a/recipes-osmocom/libosmo-netif/libosmo-netif.inc
+++ b/recipes-osmocom/libosmo-netif/libosmo-netif.inc
@@ -1,10 +1,15 @@
 DESCRIPTION = "Osmocom network interface library"
-DEPENDS = "libosmo-abis libtalloc lksctp-tools"
 HOMEPAGE = "http://git.osmocom.org"
 LICENSE = "GPLv2+"
-
-INC_PR="r0.${META_TELEPHONY_OSMO_INC}"
-
 LIC_FILES_CHKSUM = "file://COPYING;md5=751419260aa954499f7abaabaa882bbe"
 
+INC_PR="r1.${META_TELEPHONY_OSMO_INC}"
+
+DEPENDS = "libosmo-abis libtalloc"
+
+PACKAGECONFIG ??= "\
+    libsctp \
+    "
+PACKAGECONFIG[libsctp] = "--enable-libsctp,--disable-libsctp,lksctp-tools,"
+
 inherit autotools pkgconfig