rtl8188eu: Remove dead code for other than USB

The vendor code has pieces of code for PCI, SDIO, and GSPI. Remove it
and CONFIG_USB_HCI.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
rtl8188eu: Remove dead code for CONFIG_TDLS

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
rtl8188eu: Remove dead code associated with CONFIG_CONCURRENT snd CONFIG_DUALMAC_CONCURRENT

These two configuration parameters are only associated with the RTL8192DU
device, and can be removed here.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>