make: use sed instead of perl to extract lex/yacc prefix

make: use sed instead of perl to extract lex/yacc prefix

Perl is not available on certain distributions by default (e.g. Alpine
Linux). In order to avoid depending on perl just to extract the lex/yacc
prefix, use sed instead which should be available almost everywhere.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>