staging: wilc1000: fix build failure

allmodconfig build of alpha, m68k, m32r, tilepro has failed with the
error:
drivers/staging/wilc1000/wilc_wfi_cfgoperations.c: In function 'wilc_create_wiphy':
drivers/staging/wilc1000/wilc_wfi_cfgoperations.c:2632:13:
	error: 'struct wiphy' has no member named 'wowlan'

Looking at other drivers wowlan can be only used when CONFIG_PM is
defined.

Fixes: 73584a40d748 ("staging: wilc1000: add ops resuem/suspend/wakeup in cfg80211")
Cc: Glen Lee <glen.lee@atmel.com>
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wilc1000/wilc_wfi_cfgoperations.c

@@ -2629,7 +2629,9 @@ struct wireless_dev *wilc_create_wiphy(struct net_device *net, struct device *de
 	sema_init(&(priv->SemHandleUpdateStats), 1);
 	priv->wdev = wdev;
 	wdev->wiphy->max_scan_ssids = MAX_NUM_PROBED_SSID;
+#ifdef CONFIG_PM
 	wdev->wiphy->wowlan = &wowlan_support;
+#endif
 	wdev->wiphy->max_num_pmkids = WILC_MAX_NUM_PMKIDS;
 	PRINT_INFO(CFG80211_DBG, "Max number of PMKIDs = %d\n", wdev->wiphy->max_num_pmkids);