drm/bridge: Build the panel wrapper in drm_kms_helper

This fixes the following depmod error when building drm as a module:
depmod: ERROR: Found 6 modules in dependency cycles!
depmod: ERROR: Cycle detected: drm -> drm_kms_helper -> drm

Fixes: 13dfc0540a ("drm/bridge: Refactor out the panel wrapper from the lvds-encoder bridge.")
Tested-by: Lofstedt, Marta <marta.lofstedt@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/3fd262cf-1db6-4335-320c-af92f9014502@linux.intel.com

drivers/gpu/drm/Makefile

@@ -24,7 +24,6 @@ drm-$(CONFIG_COMPAT) += drm_ioc32.o
 drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o
 drm-$(CONFIG_PCI) += ati_pcigart.o
 drm-$(CONFIG_DRM_PANEL) += drm_panel.o
-drm-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o
 drm-$(CONFIG_OF) += drm_of.o
 drm-$(CONFIG_AGP) += drm_agpsupport.o
 drm-$(CONFIG_DEBUG_FS) += drm_debugfs.o drm_debugfs_crc.o
@@ -35,6 +34,7 @@ drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o \
 		drm_simple_kms_helper.o drm_modeset_helper.o \
 		drm_scdc_helper.o
 
+drm_kms_helper-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o
 drm_kms_helper-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
 drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o
 drm_kms_helper-$(CONFIG_DRM_KMS_CMA_HELPER) += drm_fb_cma_helper.o