drm/nouveau: Fix Kconfig indentation

Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
	$ sed -e 's/^        /\t/' -i */Kconfig
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20191120133619.11415-1-krzk@kernel.org

drivers/gpu/drm/nouveau/Kconfig

@@ -2,7 +2,7 @@
 config DRM_NOUVEAU
 	tristate "Nouveau (NVIDIA) cards"
 	depends on DRM && PCI && MMU
-        select FW_LOADER
+	select FW_LOADER
 	select DRM_KMS_HELPER
 	select DRM_TTM
 	select BACKLIGHT_CLASS_DEVICE if DRM_NOUVEAU_BACKLIGHT