ath9k: Remove unnecessary include of <linux/pci-aspm.h>

The ath9k driver doesn't need anything provided by pci-aspm.h, so remove
the unnecessary include of it.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Sinan Kaya <okaya@kernel.org>
Acked-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ath/ath9k/pci.c

@@ -18,7 +18,6 @@
 
 #include <linux/nl80211.h>
 #include <linux/pci.h>
-#include <linux/pci-aspm.h>
 #include <linux/module.h>
 #include "ath9k.h"