powerpc/configs: Turn CONFIG_R128 back in pmac32_defconfig

In commit d92d9c3a ("drm: hide legacy drivers with
CONFIG_DRM_LEGACY") CONFIG_R128 was moved behind CONFIG_DRM_LEGACY
meaning it stopped being enabled by pmac32_defconfig. Although no one
has noticed, given this is basically a legacy platform, it seems
anyone who is using it probably still wants this driver. So turn it
back on for now.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/configs/pmac32_defconfig

@@ -201,8 +201,9 @@ CONFIG_HWMON=m
 CONFIG_AGP=m
 CONFIG_AGP_UNINORTH=m
 CONFIG_DRM=m
-CONFIG_DRM_R128=m
 CONFIG_DRM_RADEON=m
+CONFIG_DRM_LEGACY=y
+CONFIG_DRM_R128=m
 CONFIG_FB=y
 CONFIG_FB_OF=y
 CONFIG_FB_CONTROL=y