[util/fpga] Update splice_nexysvideo.sh

Update splice script to work with new Makefile scaffolding.
diff --git a/.gitignore b/.gitignore
index 8e52be7..f1a11f5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,15 +3,21 @@
 __pycache__
 opentitan-docs
 
-#fusesoc result
+# fusesoc result
 build/
 
+# build directories with special suffixes
+build*/
+
 # Sphinx result
 _build/
 
 # JasperGold FPV Result
 jgproject/
 
+# FPGA splice intermediate files
+*.jou
+
 # Simulation Results
 *.log
 vdCovLog/