topstar-laptop - switch to using sparse keymap library

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

Acked-by: Herton Ronaldo Krzesinski <herton@mandriva.com.br>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index cff7cc2..0b11b41 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -478,6 +478,7 @@
 	tristate "Topstar Laptop Extras"
 	depends on ACPI
 	depends on INPUT
+	select INPUT_SPARSEKMAP
 	---help---
 	  This driver adds support for hotkeys found on Topstar laptops.