ath10k: increase station kickout threshold

Imported from https://patchwork.kernel.org/patch/5930881/

Description from original patch:
"Since the station kickout threshold is also counting software
reries (Default sw count in firmware is 16), increasing the threshold
to try with at least 20 data frames before kicking out the station.

Change-Id: I9b5bde622ecf2ebb82251e56c10cb1a3ff41e32e
Signed-off-by: Rajkumar Manoharan <rmanohar@qti.qualcomm.com>"
diff --git a/drivers/net/wireless/ath/ath10k/core.h b/drivers/net/wireless/ath/ath10k/core.h
index ef0f447..a20240c 100644
--- a/drivers/net/wireless/ath/ath10k/core.h
+++ b/drivers/net/wireless/ath/ath10k/core.h
@@ -49,8 +49,8 @@
 
 #define ATH10K_MAX_NUM_MGMT_PENDING 128
 
-/* number of failed packets */
-#define ATH10K_KICKOUT_THRESHOLD 50
+/* number of failed packets (20 packets with 16 sw reties each) */
+#define ATH10K_KICKOUT_THRESHOLD (20 * 16)
 
 /*
  * Use insanely high numbers to make sure that the firmware implementation