msi-wmi: Make keys and backlight independent
msi-wmi: Make keys and backlight independent

Introduced function msi_wmi_backlight_setup() that initializes backlight
device. Made driver load and work if only one WMI (only for hotkeys or
only for backlight) is present.

Signed-off-by: Maxim Mikityanskiy <fb0e63cb7ba4e5cf97330174e31a72fc18dddf57@gmail.com>
Signed-off-by: Matthew Garrett <d1dada306f6f6bc535ec5238317ee8d221588a1a@nebula.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs