ath9k: Select RELAY for ATH9K_DEBUGFS

The spectral scan support activated through ATH9K_DEBUGFS depends on RELAY for
the kernel->userspace communication. Not activating RELAY causes build
failures.

The RELAY is added as select instead of depend to do it similar like
the only other user of RELAY: BLK_DEV_IO_TRACE
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/Kconfig

@@ -58,6 +58,7 @@ config ATH9K_DEBUGFS
 	bool "Atheros ath9k debugging"
 	depends on ATH9K
 	select MAC80211_DEBUGFS
+	select RELAY
 	---help---
 	  Say Y, if you need access to ath9k's statistics for
 	  interrupts, rate control, etc.