ath10k: remove the calibration data fetch for sdio

The calibration data fetch will trigger sdio error, then sdio will
become fail untill reboot system.

If happens when run ifconfig wlan down, then ifconfig wlan up will
fail untill reboot system.Remove it fix the ifconfig wlan issue.

Tested with QCA6174 SDIO with firmware
WLAN.RMH.4.4.1-00005-QCARMSWP-1.

Signed-off-by: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>