gitignore: ignore more generated files

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

kernel/.gitignore

@@ -0,0 +1,5 @@
+#
+# Generated files
+#
+config_data.h
+config_data.gz

scripts/.gitignore

@@ -1,4 +1,7 @@
+#
+# Generated files
+#
 conmakehash
 kallsyms
 pnmtologo
-
+bin2c

scripts/kconfig/lxdialog/.gitignore

@@ -0,0 +1,4 @@
+#
+# Generated files
+#
+lxdialog