drm/mgag200: 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/20191120133625.11478-1-krzk@kernel.org

drivers/gpu/drm/mgag200/Kconfig

@@ -8,8 +8,8 @@ config DRM_MGAG200
 	select DRM_TTM_HELPER
 	help
 	 This is a KMS driver for the MGA G200 server chips, it
-         does not support the original MGA G200 or any of the desktop
-         chips. It requires 0.3.0 of the modesetting userspace driver,
-         and a version of mga driver that will fail on KMS enabled
-         devices.
+	 does not support the original MGA G200 or any of the desktop
+	 chips. It requires 0.3.0 of the modesetting userspace driver,
+	 and a version of mga driver that will fail on KMS enabled
+	 devices.