RPI Zero 2 W: Wifi not detected (Alpine 3.15.0, aarch64)

I just got a RPI Zero 2 W and I wanted to install Alpine on it. Since the Zero 2 is 64-bit capable, I wanted the aarch64 version. I started with the official tarball and the instructions on the Wiki, but swiftly ran into problems.

The first problem is that the config.txt doesn't have an entry for the pi 0, but I am given to understand that it can use the same kernel and initramfs as the pi 3, so I just copied those settings over, and it booted just fine. But it didn't have any networking hardware detected.

I've attached a dmesg log; it seems there's an issue loading the driver for the Broadcom Wifi/Bluetooth chip:

[   14.720037] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43436-sdio for chip BCM43430/2
[   14.720570] usbcore: registered new interface driver brcmfmac
[   14.725089] brcmfmac mmc1:0001:1: Direct firmware load for brcm/brcmfmac43436-sdio.raspberrypi,model-zero-2-w.bin failed with error -2
[   14.725566] brcmfmac mmc1:0001:1: Direct firmware load for brcm/brcmfmac43436-sdio.bin failed with error -2
[   14.725639] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43430b0-sdio for chip BCM43430/2
[   14.726063] brcmfmac mmc1:0001:1: Direct firmware load for brcm/brcmfmac43430b0-sdio.raspberrypi,model-zero-2-w.bin failed with error -2
[   14.726447] brcmfmac mmc1:0001:1: Direct firmware load for brcm/brcmfmac43430b0-sdio.bin failed with error -2
[   15.733709] brcmfmac: brcmf_sdio_htclk: HT Avail timeout (1000000): clkctl 0x50

This seems similar to #11408 (closed) so I tried copying the brcmfmac43430-sdio.raspberrypi,3-model-b.txt file to firmware/brcm/brcmfmac43430-sdio.raspberrypi,model-zero-2-w.txt on my boot partition, but this did not solve the issue, and at this point I'm stumped.