gitignore: ignore scripts/ihex2fw

scripts/ihex2fw is a generated binary and should be ignored
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

scripts/.gitignore

@@ -7,3 +7,4 @@ pnmtologo
 bin2c
 unifdef
 binoffset
+ihex2fw