staging: brcm80211: Fix for WPA GTK install issue in brcmfmac driver

staging: brcm80211: Fix for WPA GTK install issue in brcmfmac driver

Last 16 bytes of the key sent by cfg80211 needs to be swapped before
installing it to FW for TKIP encryption. This is not done for group
key in current code, which is corrected with this fix.

Cc: devel@linuxdriverproject.org
Cc: linux-wireless@vger.kernel.org
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Reviewed-by: Brett Rudley <brudley@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Tested-by: Grant Grundler <grundler@chromium.org>
Tested-by: Aaron Plattner <aplattner@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>