rtl8xxxu: Implement device specific power_off function

Implment 8723bu specific device power down, and make power_off() a
fileops function.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_regs.h b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_regs.h
index e0b9ea38..a8d5c9f 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_regs.h
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_regs.h
@@ -512,6 +512,8 @@
 #define REG_PKT_LOSE_RPT		0x04e1
 #define REG_PTCL_ERR_STATUS		0x04e2
 #define REG_TX_REPORT_CTRL		0x04ec
+#define  TX_REPORT_CTRL_TIMER_ENABLE	BIT(1)
+
 #define REG_TX_REPORT_TIME		0x04f0
 #define REG_DUMMY			0x04fc