sys: Remove $FreeBSD$: one-line .c comment pattern

Remove /^/[*/]\s*\$FreeBSD\$.*\n/

The diff is the initial submission of Cavium Liquidio 2350/2360 10/25G
Intelligent NIC driver.

The submission conconsists of firmware binary file and driver sources.

Submitted by: pkanneganti@cavium.com (Prasad V Kanneganti)
Relnotes: Yes
Sponsored by: Cavium Networks
Differential Revision: https://reviews.freebsd.org/D11927