staging: r8188eu: remove unused enum and array

PS_BBRegBackup in struct pwrctrl_priv is not used. Remove this component
and the related enum _PS_BBRegBackup_.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20210913185110.3065-6-martin@kaiser.cxSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/include/rtw_pwrctrl.h

@@ -53,14 +53,6 @@ enum rt_rf_power_state {
 	rf_max
 };
 
-enum _PS_BBRegBackup_ {
-	PSBBREG_RF0 = 0,
-	PSBBREG_RF1,
-	PSBBREG_RF2,
-	PSBBREG_AFE0,
-	PSBBREG_TOTALCNT
-};
-
 enum { /*  for ips_mode */
 	IPS_NONE = 0,
 	IPS_NORMAL,
@@ -125,7 +117,6 @@ struct pwrctrl_priv {
 	u8		bHWPowerdown;/* if support hw power down */
 	u8		bkeepfwalive;
 	u8		brfoffbyhw;
-	unsigned long PS_BBRegBackup[PSBBREG_TOTALCNT];
 };
 
 #define rtw_get_ips_mode_req(pwrctrlpriv) \