drm/i2c/ch7006: drop use of drmP.h

Drop using the deprecated drmP.h header file.
Fix fallout.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Emil Velikov <emil.velikov@collabora.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190716064220.18157-16-sam@ravnborg.org

drivers/gpu/drm/i2c/ch7006_priv.h

@@ -27,7 +27,6 @@
 #ifndef __DRM_I2C_CH7006_PRIV_H__
 #define __DRM_I2C_CH7006_PRIV_H__
 
-#include <drm/drmP.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_encoder_slave.h>
 #include <drm/drm_probe_helper.h>