Input: add keyboard notifier documentation
Input: add keyboard notifier documentation

Document the keyboard notifier.

Signed-off-by: Samuel Thibault <49a5ed162141aa1a2ad45c2f70540ac844521912@ens-lyon.org>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Jiri Kosina <ed58f755cc8caaf10c3e8c731a8b86fb8f13d6cb@suse.cz>
SIgned-off-by: Dmitry Torokhov <10a8c465cefc9bdd6c925e26964d23c90f1141cc@mail.ru>

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