Realtek wireless firmwares imported!

As a result of a licence change by Realtek, that company's wireless firmware images are now included in the tree. The following commit by Kevin Lo (kevlo@) explains the details:

CVSROOT:	/cvs
Module name:	src
Changes by:	kevlo@cvs.openbsd.org	2021/10/03 19:29:57

Added files:
	sys/dev/microcode/rsu: microcode.h rsu-license 
	sys/dev/microcode/rtwn: microcode.h rtwn-license 
	sys/dev/microcode/urtwn: microcode.h urtwn-license 

Log message:
Permission from Realtek to include wireless firmwares

After deraadt@ explained why the Realtek firmware cannot be put into our tree,
I reached out to Realtek to explain the situation.

According to the LICENCE.rtlwifi_firmware.txt [1], the rules permitted adding
their non-open-source firmware into open source operating systems but such
an addition (ironically) makes that open source operating system not entirely
open source.  Realtek understood the irony, and change the license.

Thanks to Realtek for this change which lets us put the firmware .h file
into our tree, this means Realtek wireless will work without requiring
a firmware download (which is difficult over a non-working Realtek network :)

[1] https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/tree/LICENCE.rtlwifi_firmware.txt?id=0f863ff1b388ad5b0f7d25decdbb642#n22


ok deraadt@

Thanks to Realtek, Kevin, and Theo!

This change should be particularly welcome with users of the popular urtwn(4) devices.