x11-drivers/xf86-video-sis: Update to 0.11.0

Update x11-drivers/xf86-video-sis to 0.11.0
Remove dependency on mesa and libGL, it is not used
Add license information
This is a maintenance release
This has not been tested with actual hardware.

Changelog:
https://lists.x.org/archives/xorg-announce/2019-July/003016.html

Obtained from: FreeBSD Graphics Team development repo

		https://github.com/FreeBSDDesktop/freebsd-ports/tree/feature/xorglibs