brcmfmac: move "cfg80211_ops" pointer to another struct

This moves "ops" pointer from "struct brcmf_cfg80211_info" to the
"struct brcmf_pub". This movement makes it possible to allocate wiphy
without attaching cfg80211 (brcmf_cfg80211_attach()). It's required for
later separation of wiphy allocation and driver initialization.

While at it fix also an unlikely memory leak in the brcmf_attach().

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>