wil6210: update FW file name

Firmware "board" file name has changed from wil6210.board
to wil6210.brd by the FW generation tools.

Reflect this in the driver.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NKalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/wil6210/wil6210.h

@@ -33,7 +33,7 @@ extern bool debug_fw;
 
 #define WIL_NAME "wil6210"
 #define WIL_FW_NAME "wil6210.fw" /* code */
-#define WIL_FW2_NAME "wil6210.board" /* board & radio parameters */
+#define WIL_FW2_NAME "wil6210.brd" /* board & radio parameters */
 
 #define WIL_MAX_BUS_REQUEST_KBPS 800000 /* ~6.1Gbps */