ath10k: add reset ctrl related functions in ahb

To perform reset on qca4019 wifi, multiple reset lines needs
to be toggled in a sequence with help of reset controller support
in the kernel. This patch adds functions to reset control init/deinit
and release reset.

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