Staging: panel: Adjust range for PANEL_KEYPAD in Kconfig

In panel.c there are only the values 0-3 defined. So 4 is invalid:
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/panel/Kconfig

@@ -47,7 +47,7 @@ config PANEL_PROFILE
 config PANEL_KEYPAD
 	depends on PANEL && PANEL_PROFILE="0"
 	int "Keypad type (0=none, 1=old 6 keys, 2=new 6 keys, 3=Nexcom 4 keys)"
-	range 0 4
+	range 0 3
 	default 0
 	---help---
 	  This enables and configures a keypad connected to the parallel port.