For that, you need to go to the following path in the Linux terminal, ~/myandroid/kernel_imx, and type "make menuconfig".
When the kernel configuration menu appears, you need to go to:
Device Drivers --->
Network device support --->
Wireless LAN --->
Press space bar in: Redpine Signal Inc 91x WLAN driver support and save the configuration, without changing the name.
But, you need to build your kernel image separately.
I hope this can solve your problem.