staging: r8188eu: Fix smatch warning in hal/HalPhyRf_8188e.c

Smatch reported the following warning:
drivers/staging/rtl8188eu/hal/HalPhyRf_8188e.c:1876 PHY_APCalibrate_8188E() info: ignoring unreachable code.

Once the unreachable code was removed, the entire routine was removed, which
led to the warning that phy_APCalibrate_8188E() was not used. It was also deleted
along with some unused defines.
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/include/HalPhyRf_8188e.h

@@ -45,8 +45,6 @@ void PHY_IQCalibrate_8188E(struct adapter *Adapter, bool ReCovery);
 void PHY_LCCalibrate_8188E(struct adapter *pAdapter);
 
 /*  AP calibrate */
-void PHY_APCalibrate_8188E(struct adapter *pAdapter, s8 delta);
-
 void PHY_DigitalPredistortion_8188E(struct adapter *pAdapter);
 
 void _PHY_SaveADDARegisters(struct adapter *pAdapter, u32 *ADDAReg,