Makefile.am: dropped bison flags: -y -d --no-lines.

Makefile.am: dropped bison flags: -y -d --no-lines.

-y stands for yacc compatibility, we don't need it since we no longer
accept yacc instead of bison.

-d stands for defines file, we already specify that in makefile rule
for parser.

--no-lines is generally useless and didn't have any effect for some
reason (#line directives are present).