brcmfmac: only support the BCM43455/7 device

Recently support was added for the BCM4345 SDIO chipset by
commit 9c510265 ("brcmfmac: Add support for BCM4345 SDIO chipset")
however this was verified using a BCM43455 device, which is
a more recent revision of the chip. This patch assure that
older revisions are not probed as they would fail.

Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Syed Asifful Dayyan <syedd@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>