panasonic-laptop - switch to using sparse keymap library

nstead of implementing its own version of keymap hanlding switch over to
using sparse keymap library.

Cc: Harald Welte <laforge@gnumonks.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

diff --cc drivers/platform/x86/Kconfig
Simple merge

diff --cc drivers/platform/x86/panasonic-laptop.c
Simple merge