brcmfmac: rework driver initialization in brcmf_bus_start()

In brcmf_bus_start() a number of settings are sent to the device. For
this functions are used that bypass the common firmware interface.
By reordering the code in brcmf_bus_start() this bypass can be removed.

Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>