staging: brcm80211: fix suspend/resume issue in brcmsmac

PCI PM suspend callback took down the interface and resume brought
it back up. In the mac80211 context this is done in subsequent calls.
Rework implementation so that suspend only stores config, and sets
PCI power state. The resume return to full power state (D0), restores
the config, and brings hardware back up. Full bringup is done by
subsequent mac80211 calls.

Reviewed-by: Brett Rudley <brudley@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>