brcmfmac: use struct brcmf_if instance as parameter in brcmf_set_mpc()

brcmfmac: use struct brcmf_if instance as parameter in brcmf_set_mpc()

Remove use of struct netdevice as parameter to brcmf_set_mpc() as it
will not always be available, ie. there will be non-netdevice interfaces.

Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Piotr Haber <phaber@broadcom.com>
Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>