drm/mxm: fix Kconfig options for when to build MXM WMI driver.

	select FRAMEBUFFER_CONSOLE if !EXPERT

	select FB_BACKLIGHT if DRM_NOUVEAU_BACKLIGHT

	select ACPI_VIDEO if ACPI && X86 && BACKLIGHT_CLASS_DEVICE && VIDEO_OUTPUT_CONTROL && INPUT

	select MXM_WMI if ACPI

	select MXM_WMI if ACPI && ACPI_WMI

	help

	  Choose this option for open-source nVidia support.

config MXM_WMI

       tristate "WMI support for MXM Laptop Graphics"

       depends on WMI

       depends on ACPI_WMI

       ---help---

          MXM is a standard for laptop graphics cards, the WMI interface

	  is required for switchable nvidia graphics machines