net: wireless: rockchip_wlan: update realtek wifi support

net: wireless: rockchip_wlan: update realtek wifi support

support wifi driver work as ko module or compile into kernel

1. wifi driver work as ko module, configs show as below:

CONFIG_WIFI_LOAD_DRIVER_WHEN_KERNEL_BOOTUP=n
CONFIG_RTL8188EU = m and CONFIG_RTL8188FU = m

2. wifi driver compile into kernel, configs show as below:
ps: Only one Realtek driver can be compiled into the kernel
CONFIG_WIFI_LOAD_DRIVER_WHEN_KERNEL_BOOTUP=y
CONFIG_RTL8188EU = y or CONFIG_RTL8188FU = y

Change-Id: I40e33a6f27597f9f90d9987d189b74fb637c40c1
Signed-off-by: Xu Xuehui <xxh@rock-chips.com>