debian/rules: make configure args diff friendly

Have one arg per line, and order it mostly alphabetically while at it
(backends are still together, as recommended in review).

Change-Id: I354affacb38958efe70baedc6175aeab525190a6
diff --git a/debian/rules b/debian/rules
index 5795643..e6cac87 100755
--- a/debian/rules
+++ b/debian/rules
@@ -9,7 +9,14 @@
 	dh_shlibdeps --dpkg-shlibdeps-params=--ignore-missing-info
 
 override_dh_auto_configure:
-	dh_auto_configure -- --with-uhd --with-usrp1 --with-lms --with-ipc --with-systemdsystemunitdir=/lib/systemd/system --enable-manuals
+	dh_auto_configure -- \
+		--enable-manuals \
+		--with-systemdsystemunitdir=/lib/systemd/system \
+		--with-ipc \
+		--with-lms \
+		--with-uhd \
+		--with-usrp1 \
+		$(NULL)
 
 override_dh_strip:
 	dh_strip --dbg-package=osmo-trx-dbg