linux-firmware-rpidistro: Borken symlink on scarthgap

[ashlin4010]

Description
In builds of Scarthgap (might also affect others) brcmfmac tries to load brcm/brcmfmac43455-sdio.raspberrypi,4-model-b.bin which points to cypress/cyfmac43455-sdio.bin which does not exist.

Steps to reproduce the issue:

1. Build poky with meta-raspberrypi + brcmfmac + linux-firmware-rpidistro
2. Check dmesg

Describe the results you received:
In dmesg you will see an error like this:

brcmfmac mmc1:0001:1: Direct firmware load for brcm/brcmfmac43455-sdio.raspberrypi,4-model-b.bin failed with error -2

General Fix
A new patch file will need to be made like 0001-Default-43455-firmware-to-standard-variant.patch to link cyfmac43455-sdio.bin to cyfmac43455-sdio-standard.bin.

Sorry I can make a PR for this, I don't have the time currently.

Version info
meta-raspberrypi: 6df7e02
Tested board: raspberry pi 4 model b
Firmware: 4b356e134e8333d073bd3802d767a825adec3807

Extra Stuff
There is another issue that has to do with this and other issues around wifi, see #1388

Thank you