brcmfmac: update BRCMFMAC symbol description

For quite some time now brcmfmac supports 802.11ac chipsets and it's
not limited to embedded devices only. There are even standalone PCIe
cards based on BCM43602 or BCM4366.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>