ath10k: update MODULE_FIRMWARE definitions for QCA6174

This has been missed while adding the QCA6174 support.
As in the last time, without advertising the firmware files
as needed (or optional) for ath10k, these won't be built into
ram disk for instance.

Signed-off-by: Bartosz Markowski <bartosz.markowski@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>