gitignore: ignore files generated by Automake's testsuite

These files are generated by Automake 1.13 when running the testsuite.
diff --git a/testsuite/.gitignore b/testsuite/.gitignore
index 9706d3c..71f34cc 100644
--- a/testsuite/.gitignore
+++ b/testsuite/.gitignore
@@ -14,3 +14,23 @@
 /test-modprobe
 /rootfs
 /stamp-rootfs
+/test-alias.log
+/test-alias.trs
+/test-blacklist.log
+/test-blacklist.trs
+/test-dependencies.log
+/test-dependencies.trs
+/test-depmod.log
+/test-depmod.trs
+/test-init.log
+/test-init.trs
+/test-loaded.log
+/test-loaded.trs
+/test-modinfo.log
+/test-modinfo.trs
+/test-modprobe.log
+/test-modprobe.trs
+/test-new-module.log
+/test-new-module.trs
+/test-testsuite.log
+/test-testsuite.trs