ath10k: add FW API 6 firmware image for QCA9377

Firmware WLAN.TF.2.1-00014-QCARMSWP-1 now supports reading the board ID
information and also required 9 IRAM bank, which older ath10k version
don't have the support will fail to be enabled, so in order to maintain
the backward compatibility, we need to update the FW API to 6.

Signed-off-by: Ryan Hsu <ryanhsu@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>