patch(1): Add dry-run alias for compatibility with other implementations

Other implementations of patch(1), including GNU patch, "svn patch" and
FreeBSD patch have a --dry-run option which does the same as our -C or
--check option.

Add --dry-run alias to increase compatibility.

Taken-from: FreeBSD
camcontrol(8): Add '-b' flag to 'camcontrol devlist'

This prints only the existing buses and their parent sims, useful for
creating a sim->bus->device map.

Taken-from: FreeBSD
drm: Add linux/mm.h

Obtained-from: FreeBSD's OFED framework
drm: Use the ERESTARTSYS error code

* Linux kernel functions can return -ERESTARTSYS in some cases, a
  negative value indicating an error (typically -512)

* Howewer, ERESTARTSYS was previously as ERESTART, itself defined
  as -1 in *BSD kernels

* The -ERESTARTSYS return value thus was positive on the DragonFly
  kernel, potentially breaking various drm error checks.

* Fix this issue by defining ERESTARTSYS separately

Thanks-to: Imre Vadasz for discovering the original problem
proto: ctlinput is a pr method; not a pru method
icmp: Use inet_ntop() to log ip addresses
rc.subr: Add required_modules processing.

This will kldload appropriate modules, needed by some dports (e.g.
openvpn).

Obtained-from:   FreeBSD