sys/amd64/conf/LINT-NOINET{6,}: don't set WITHOUT_INET{6,}_SUPPORT

Previously, it was necessary to set WITHOUT_INET_SUPPORT when building
the kernel without INET, and WITHOUT_INET6_SUPPORT when building the
kernel without INET6, or else the modules build would fail. The
LINT-NOINET and LINT-NOINET6 configs did this using makeoptions.

After recent changes, this is no longer required, so remove these
makeoptions. This avoids masking potential future build issues when
these aren't set.

Reviewed by: imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/1255