ath6kl: Invoke WOW suspend/resume calls during PM operation

Link ath6kl's wow suspend/resume functions with the actual suspend/resume path.

WOW mode is selected when the host sdio controller supports both
MMC_PM_KEEP_POWER and MMC_PM_WAKE_SDIO_IRQ capabilities.

kvalo: also adds a missing break in ath6kl_cfg80211_resume(), luckily
it didn't have any effect on functionality.

Signed-off-by: Raja Mani <rmani@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>