ath10k: support MAC address randomization in scan

The ath10k reports the random_mac_addr capability to upper layer
based on the service bit firmware reported. Driver sets the
spoofed flag in scan_ctrl_flag to firmware if upper layer has
enabled this feature in scan request.

Test with QCA6174 hw3.0 and firmware-6.bin_WLAN.RM.4.4.1-00102-QCARMSWP-1,
but QCA9377 is also affected.

Signed-off-by: Carl Huang <cjhuang@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>