drm/hisilicon: Don't set drm_device->platformdev

It's deprecated and only should be used by drivers which still use
drm_platform_init, not by anyone else.

And indeed it's entirely unused and can be nuked.

This required a bit more fudging, but I guess kirin_dc_ops really
wants to operate on the platform_device, not something else. Also
bonus points for implementing abstraction, and then storing the vfunc
in a global variable.

v2: Don't break the build soooo badly :(
Note that the cleanup function is a bit confused: ade_data was never
set as drvdata, and calling drm_crtc_cleanup directly is a bug - this
is called indirectly through drm_mode_config_cleanup, which calls into
crtc->destroy, which already has the call to drm_crtc_cleanup. Which
means we can just nuke it.

Note this is the 2nd attempt after the first one failed and had to be
reverted again in

commit 9cd2e854d61ccfa51686f3ed7b0c917708fc641f
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Aug 17 13:59:40 2016 +0200

    Revert "drm/hisilicon: Don't set drm_device->platformdev"

Cc: Xinliang Liu <xinliang.liu@linaro.org>
Cc: Xinwei Kong <kong.kongxinwei@hisilicon.com>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161209141944.22121-1-daniel.vetter@ffwll.ch

drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c

@@ -973,9 +973,9 @@ static int ade_dts_parse(struct platform_device *pdev, struct ade_hw_ctx *ctx)
 	return 0;
 }
 
-static int ade_drm_init(struct drm_device *dev)
+static int ade_drm_init(struct platform_device *pdev)
 {
-	struct platform_device *pdev = dev->platformdev;
+	struct drm_device *dev = platform_get_drvdata(pdev);
 	struct ade_data *ade;
 	struct ade_hw_ctx *ctx;
 	struct ade_crtc *acrtc;
@@ -1034,13 +1034,8 @@ static int ade_drm_init(struct drm_device *dev)
 	return 0;
 }
 
-static void ade_drm_cleanup(struct drm_device *dev)
+static void ade_drm_cleanup(struct platform_device *pdev)
 {
-	struct platform_device *pdev = dev->platformdev;
-	struct ade_data *ade = platform_get_drvdata(pdev);
-	struct drm_crtc *crtc = &ade->acrtc.base;
-
-	drm_crtc_cleanup(crtc);
 }
 
 const struct kirin_dc_ops ade_dc_ops = {

drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c

@@ -42,7 +42,7 @@ static int kirin_drm_kms_cleanup(struct drm_device *dev)
 #endif
 	drm_kms_helper_poll_fini(dev);
 	drm_vblank_cleanup(dev);
-	dc_ops->cleanup(dev);
+	dc_ops->cleanup(to_platform_device(dev->dev));
 	drm_mode_config_cleanup(dev);
 	devm_kfree(dev->dev, priv);
 	dev->dev_private = NULL;
@@ -104,7 +104,7 @@ static int kirin_drm_kms_init(struct drm_device *dev)
 	kirin_drm_mode_config_init(dev);
 
 	/* display controller init */
-	ret = dc_ops->init(dev);
+	ret = dc_ops->init(to_platform_device(dev->dev));
 	if (ret)
 		goto err_mode_config_cleanup;
 
@@ -138,7 +138,7 @@ static int kirin_drm_kms_init(struct drm_device *dev)
 err_unbind_all:
 	component_unbind_all(dev->dev, dev);
 err_dc_cleanup:
-	dc_ops->cleanup(dev);
+	dc_ops->cleanup(to_platform_device(dev->dev));
 err_mode_config_cleanup:
 	drm_mode_config_cleanup(dev);
 	devm_kfree(dev->dev, priv);
@@ -209,8 +209,6 @@ static int kirin_drm_bind(struct device *dev)
 	if (IS_ERR(drm_dev))
 		return PTR_ERR(drm_dev);
 
-	drm_dev->platformdev = to_platform_device(dev);
-
 	ret = kirin_drm_kms_init(drm_dev);
 	if (ret)
 		goto err_drm_dev_unref;

drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.h

@@ -15,8 +15,8 @@
 
 /* display controller init/cleanup ops */
 struct kirin_dc_ops {
-	int (*init)(struct drm_device *dev);
-	void (*cleanup)(struct drm_device *dev);
+	int (*init)(struct platform_device *pdev);
+	void (*cleanup)(struct platform_device *pdev);
 };
 
 struct kirin_drm_private {