rtl8xxxu: Use flag to indicate whether device has TX report timer support

Use a fileops flag to indicate whether the device has TX report timer
support. This will make it easier to include future devices such as
8188eu to use the TX report timer.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h

@@ -1341,6 +1341,7 @@ struct rtl8xxxu_fileops {
 	char tx_desc_size;
 	char rx_desc_size;
 	char has_s0s1;
+	char has_tx_report;
 	u32 adda_1t_init;
 	u32 adda_1t_path_on;
 	u32 adda_2t_path_on_a;

drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c

@@ -1666,6 +1666,7 @@ struct rtl8xxxu_fileops rtl8723bu_fops = {
 	.tx_desc_size = sizeof(struct rtl8xxxu_txdesc40),
 	.rx_desc_size = sizeof(struct rtl8xxxu_rxdesc24),
 	.has_s0s1 = 1,
+	.has_tx_report = 1,
 	.adda_1t_init = 0x01c00014,
 	.adda_1t_path_on = 0x01c00014,
 	.adda_2t_path_on_a = 0x01c00014,

drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c

@@ -4000,10 +4000,9 @@ static int rtl8xxxu_init_device(struct ieee80211_hw *hw)
 		priv->fops->usb_quirks(priv);
 
 		/*
-		 * Presumably this is for 8188EU as well
-		 * Enable TX report and TX report timer
+		 * Enable TX report and TX report timer for 8723bu/8188eu/...
 		 */
-		if (priv->rtl_chip == RTL8723B) {
+		if (priv->fops->has_tx_report) {
 			val8 = rtl8xxxu_read8(priv, REG_TX_REPORT_CTRL);
 			val8 |= TX_REPORT_CTRL_TIMER_ENABLE;
 			rtl8xxxu_write8(priv, REG_TX_REPORT_CTRL, val8);