rtl8723au: Remove "#if 1" statements and associated dead code

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
rtl8723au: Remove CONFIG_RTLxxx configuration lines

This driver is only useful for RTL8723AU devices, thus all tests for this and
other devices is removed.

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