asus-nb-wmi: Add ASUSTeK COMPUTER INC. X200CA

BIOS won't light on the wifi-led after S3, so asus-wmi driver needs to
control the wifi and wifi-led status.
But, it'll lead to bt status error if asus-wmi driver controls bt as well.
So, for X200CA, asus-wmi driver controls wifi status only and have to set
wapf to 1.

Signed-off-by: AceLan Kao <acelan.kao@canonical.com>
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>