brcmfmac: add support for BCM4324 rev B5 chipset

This patch adds support for the BCM4324 B5 revision. This device
is similar to BCM43241 from driver and firmware perspective. It
is known to be used in Lenovo Thinkpad Tablet devices.

Reviewed-by: Hante Meuleman <meuleman@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>