sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

cxgbe(4): Initial import of the "collect" component of Chelsio unified
debug (cudbg) code, hooked up to the main driver via an ioctl.

The ioctl can be used to collect the chip's internal state in a
compressed dump file. These dumps can be decoded with the "view"
component of cudbg.

Obtained from: Chelsio Communications
MFC after: 2 months
Sponsored by: Chelsio Communications