linux-firmware : Add firmware of RTL8822 serie

RTL8822 is a serie of wireless modules that need firmwares to function correctly.
The linux firmware recipe does not have a package of these firmwares, and this commit add them.

Signed-off-by: BELOUARGA Mohamed <m.belouarga@technologyandstrategy.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>