wlcore: Remove unused macro WL1271_SUSPEND_SLEEP

commit 45aa7f07 ("wlcore: Use generic runtime pm calls for wowlan elp configuration")
left behind this, remove it.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200909135905.35728-1-yuehaibing@huawei.com