net/intel-em-kmod: Update to 7.7.4, enable netmap on 11

• Update PORTVERSION and distinfo
• Extend netmap options to slave ports too
• Add option to set maximum supported os version w/netmap for slave ports in intel-ixl-kmod
• Mark the port as non-netmap by default for 12+, as the driver doesn't build with netmap support atm

Compile and sanity tested using poudriere w/portlint

Reviewed By: sbruno (mentor), franco_opnsense.org (maintainer)

Differential Revision: https://reviews.freebsd.org/D17440