brcm: add firmware for BCM43143 2.4G 11n USB device

This firmware is for the BCM43143 USB which is a low-cost
11n chip capable of using 40MHz bandwidth.
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

WHENCE

@@ -1736,6 +1736,7 @@ File: brcm/brcmfmac4335-sdio.bin
 File: brcm/brcmfmac43362-sdio.bin
 File: brcm/brcmfmac43241b0-sdio.bin
 File: brcm/brcmfmac43241b4-sdio.bin
+File: brcm/brcmfmac43143.bin
 
 Licence: Redistributable. See LICENCE.broadcom_bcm43xx for details.