drm: imx: imx-hdmi: move imx-hdmi to bridge/dw_hdmi

the original imx hdmi driver is under drm/imx/,
which depends on imx-drm, so move the imx hdmi
driver out to drm/bridge and rename it to dw_hdmi

Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
diff --git a/drivers/gpu/drm/imx/Makefile b/drivers/gpu/drm/imx/Makefile
index 63cf56a..f3ecd89 100644
--- a/drivers/gpu/drm/imx/Makefile
+++ b/drivers/gpu/drm/imx/Makefile
@@ -9,4 +9,4 @@
 
 imx-ipuv3-crtc-objs  := ipuv3-crtc.o ipuv3-plane.o
 obj-$(CONFIG_DRM_IMX_IPUV3)	+= imx-ipuv3-crtc.o
-obj-$(CONFIG_DRM_IMX_HDMI) += imx-hdmi.o imx-hdmi_pltfm.o
+obj-$(CONFIG_DRM_IMX_HDMI) += dw_hdmi-imx.o