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>