brcmfmac: fix brcmf_wiphy_wowl_params() NULL pointer dereference

The kernel BUG happens when wowl is enabled from firmware. In
brcmf_wiphy_wowl_params(), cfg is a NULL pointer because it is
drvr->config returned from wiphy_to_cfg(), and drvr->config is not set
yet. To fix it, set drvr->config before brcmf_setup_wiphy() which
calls brcmf_wiphy_wowl_params().

Fixes: 856d5a01 ("brcmfmac: allocate struct brcmf_pub instance using wiphy_new()")
Signed-off-by: Winnie Chang <winnie.chang@cypress.com>
Signed-off-by: Chi-Hsien Lin <chi-hsien.lin@cypress.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c

@@ -6926,15 +6926,15 @@ struct brcmf_cfg80211_info *brcmf_cfg80211_attach(struct brcmf_pub *drvr,
 	cfg->d11inf.io_type = (u8)io_type;
 	brcmu_d11_attach(&cfg->d11inf);
 
-	err = brcmf_setup_wiphy(wiphy, ifp);
-	if (err < 0)
-		goto priv_out;
-
 	/* regulatory notifer below needs access to cfg so
 	 * assign it now.
 	 */
 	drvr->config = cfg;
 
+	err = brcmf_setup_wiphy(wiphy, ifp);
+	if (err < 0)
+		goto priv_out;
+
 	brcmf_dbg(INFO, "Registering custom regulatory\n");
 	wiphy->reg_notifier = brcmf_cfg80211_reg_notifier;
 	wiphy->regulatory_flags |= REGULATORY_CUSTOM_REG;