ath5k: disable 32KHz sleep clock operation by default

While 32 KHz sleep clock might provide some power saving benefits,
it is also a major source of stability issues, on OpenWrt it produced
some reproducible data bus errors on register accesses on several
different MIPS platforms.

All the Atheros drivers that I can find do not enable this feature,
so it makes sense to leave it disabled in ath5k as well.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath5k/debug.c b/drivers/net/wireless/ath/ath5k/debug.c
index ae1112b..4edca70 100644
--- a/drivers/net/wireless/ath/ath5k/debug.c
+++ b/drivers/net/wireless/ath/ath5k/debug.c
@@ -922,6 +922,9 @@
 
 	debugfs_create_file("queue", S_IWUSR | S_IRUSR, phydir, sc,
 			    &fops_queue);
+
+	debugfs_create_bool("32khz_clock", S_IWUSR | S_IRUSR, phydir,
+			    &sc->ah->ah_use_32khz_clock);
 }
 
 /* functions used in other places */