brcmfmac: Fix a memory leak in error handling path in 'brcmf_cfg80211_attach'

If 'wiphy_new()' fails, we leak 'ops'. Add a new label in the error
handling path to free it in such a case.

Cc: stable@vger.kernel.org
Fixes: 5c22fb85

 ("brcmfmac: add wowl gtk rekeying offload support")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>