drm/radeon: fix power supply kconfig interaction.

radeon needs power supply to get correct PM info so select it at the radeon
level not at the kms option.

Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 2583ddf..88910e5 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -60,6 +60,7 @@
 	select FW_LOADER
         select DRM_KMS_HELPER
         select DRM_TTM
+	select POWER_SUPPLY
 	help
 	  Choose this option if you have an ATI Radeon graphics card.  There
 	  are both PCI and AGP versions.  You don't need to choose this to