drm/vmwgfx: select CONFIG_FB

vmwgfx doesn't actually build without that.

It would be great if vmwgfx could switch over to the fbdev emulation
helpers, since those will take care of all this already. I guess one
reason to not do that was lack of defio support in the helpers, but
that's fixed now. If there's any other hold-up, we should figure out
what it is and whether it makes sense to address it.

Cc: Sinclair Yeh <syeh@vmware.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470847958-28465-4-git-send-email-daniel.vetter@ffwll.ch

drivers/gpu/drm/vmwgfx/Kconfig

@@ -6,6 +6,7 @@ config DRM_VMWGFX
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
 	select DRM_TTM
+	select FB
 	# Only needed for the transitional use of drm_crtc_init - can be removed
 	# again once vmwgfx sets up the primary plane itself.
 	select DRM_KMS_HELPER