ath10k: reset chip before reading chip_id in probe

There are some very rare cases with some hardware
configuration that the device doesn't init quickly
enough in which case reading chip_id yielded 0.
This caused driver to subsequently fail to setup
the device.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>