cmake: make formatting of install statements follow one pattern

Change-Id: Ib7d571af629b0af78397a411b0cca409a6d218d8
diff --git a/grc/receiver/CMakeLists.txt b/grc/receiver/CMakeLists.txt
index 3db5983..06a3c0c 100644
--- a/grc/receiver/CMakeLists.txt
+++ b/grc/receiver/CMakeLists.txt
@@ -17,7 +17,8 @@
 # the Free Software Foundation, Inc., 51 Franklin Street,
 # Boston, MA 02110-1301, USA.
 
-install(FILES
+install(
+    FILES
     gsm_input.block.yml
     gsm_receiver.block.yml
     gsm_receiver_with_uplink.block.yml