linux-firmware: create separate package for cirrus and cnm firmwares

linux-firmware: create separate package for cirrus and cnm firmwares

This is cherry-pick of commit 3ddddfc14f805fe7572bba129605869fb848fed4 from
poky master.

Some licenses only allow usage of corresponding firmwares when a specific
hardware is present. This requires split of such firmwares from linux-firmware
package to firmware specific sub package. As this split is based off of
licensing, it makes sense to group firmware blobs having the same license in the
same package. This commit is a first step in this direction, and creates
separate packages for cirrus and cnm firmware.

(From OE-Core rev: 53d9d8789efc701609a5a1e985287344c2209d62)

Signed-off-by: Fahad Arslan <fahad.arslan@siemens.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Steve Sakoman <steve@sakoman.com>