platform/x86: Make SILEAD_DMI depend on TOUCHSCREEN_SILEAD

SILEAD_DMI provides platform specific data for the TOUCHSCREEN_SILEAD
driver. Make this explicitly clear in the Kconfig depends. Remove
INPUT as this is implied by TOUCHSCREEN_SILEAD.

Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Andy Shevchenko <andy@infradead.org>
Cc: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/platform/x86/Kconfig

@@ -1101,7 +1101,7 @@ config INTEL_TURBO_MAX_3
 
 config SILEAD_DMI
 	bool "Tablets with Silead touchscreens"
-	depends on ACPI && DMI && I2C=y && INPUT
+	depends on ACPI && DMI && I2C=y && TOUCHSCREEN_SILEAD
 	---help---
 	  Certain ACPI based tablets with Silead touchscreens do not have
 	  enough data in ACPI tables for the touchscreen driver to handle