ath10k: add platform regulatory domain support

This overrides whatever regulatory the device
EEPROM contains and uses what the platform says
instead - in this implementation the ACPI driver.

In case the hint is not programmed or corrupted (0xffff)
the device falls back to the eeprom programmed settings.

Signed-off-by: Bartosz Markowski <bartosz.markowski@tieto.com>
[kvalo@qca.qualcomm.com: remove ifdef, change error handling, change info messages to dbg]
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>