Historically the port has used GNU_CONFIGURE but this is not needed.
Switch to HAS_CONFIGURE and adjust the needed configure args.
Commit message:
```
net/dhcpcd: Use HAS_CONFIGURE over GNU_CONFIGURE
Historically the port has used GNU_CONFIGURE but this is not needed.
Switch to HAS_CONFIGURE and adjust the needed configure args.
Reported by: diizzy
Reviewed by: diizzy
Approved by: tbd (mentor)
Differential Revision: https://reviews.freebsd.org/D32907
```