brcmfmac: add BCM4354 SDIO interface support

BCM4354 is an a/b/g/n/ac 2x2 WiFi chip. This patch adds support for it through
SDIO interface.

Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Signed-off-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>