wlcore: align reg_ch_conf_last[] to 64bit

Align fields reg_ch_conf_last and reg_ch_conf_pending of
struct wl1271{} to 64bit.

Without this, on 64bit ARM, wlcore_set_pending_regdomain_ch() fails at
the point it calls set_bit(ch_bit_idx, (long*)wl->reg_ch_conf_pending);
Here is the error message while doing iw wlan0 scan or connect:

[   10.666857] wlcore: IRQ work
[   10.670046] wlcore: intr: 0x40 (fw_rx_counter = 1, drv_rx_counter = 0, tx_results_counter = 0)
[   10.678697] wlcore: WL1271_ACX_INTR_DATA
[   10.682810] Unhandled fault: alignment fault (0x96000021) at 0xffffffc037a817f4
[   10.690139] Internal error: : 96000021 [#1] PREEMPT SMP
[   10.695366] Modules linked in:
[   10.698437] CPU: 3 PID: 894 Comm: irq/60-wl18xx Tainted: G        W       4.2.0-rc6-linaro-hikey #2
[   10.707501] Hardware name: HiKey Development Board (DT)
[   10.712733] task: ffffffc03a9d1680 ti: ffffffc039e18000 task.ti: ffffffc039e18000
[   10.720239] PC is at set_bit+0x14/0x30
[   10.724002] LR is at wlcore_set_pending_regdomain_ch+0x40/0x4c
Signed-off-by: Guodong Xu <guodong.xu@linaro.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ti/wlcore/wlcore.h

@@ -318,7 +318,7 @@ struct wl1271 {
 	bool watchdog_recovery;
 
 	/* Reg domain last configuration */
-	u32 reg_ch_conf_last[2];
+	u32 reg_ch_conf_last[2]  __aligned(8);
 	/* Reg domain pending configuration */
 	u32 reg_ch_conf_pending[2];