platform/x86: fujitsu-laptop: use a sparse keymap for brightness key events

Simplify brightness key event generation by using a sparse keymap.

Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Jonathan Woithe <jwoithe@just42.net>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index e1bffc9..5602bdf 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -183,6 +183,7 @@
 	depends on BACKLIGHT_CLASS_DEVICE
 	depends on ACPI_VIDEO || ACPI_VIDEO = n
 	depends on LEDS_CLASS || LEDS_CLASS=n
+	select INPUT_SPARSEKMAP
 	---help---
 	  This is a driver for laptops built by Fujitsu: