sys: Remove $FreeBSD$: one-line sh pattern

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

sys/modules: normalize .CURDIR-relative paths to SRCTOP

This simplifies make output/logic

Tested with: `cd sys/modules; make ALL_MODULES=` on amd64
MFC after: 1 month
Sponsored by: Dell EMC Isilon

Driver 'aacraid' added. Supports Adaptec by PMC RAID controller families Series 6, 7, 8 and upcoming products. Older Adaptec RAID controller families are supported by the 'aac' driver.

Approved by: scottl (mentor)