cfg80211: pass wiphy to cfg80211_ref_bss/put_bss

This prepares for using the spinlock instead of krefs
which is needed in the next patch to track the refs
of combined BSSes correctly.

Acked-by: Bing Zhao <bzhao@marvell.com> [mwifiex]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>