drm: drop use of drmP.h in drm/*

The use of the drmP.h header file is deprecated.
Remove use from all files in drm/*
so people do not look there and follow a bad example.

Build tested allyesconfig,allmodconfig on x86, arm etc.
Including alpha that is as always more challenging than
the rest.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: David Airlie <airlied@linux.ie>
Link: https://patchwork.freedesktop.org/patch/msgid/20190526173535.32701-8-sam@ravnborg.org
diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c
index f5cb0aa..a17c8a1 100644
--- a/drivers/gpu/drm/drm_print.c
+++ b/drivers/gpu/drm/drm_print.c
@@ -26,8 +26,13 @@
 #define DEBUG /* for pr_debug() */
 
 #include <stdarg.h>
+
+#include <linux/io.h>
 #include <linux/seq_file.h>
-#include <drm/drmP.h>
+#include <linux/slab.h>
+
+#include <drm/drm.h>
+#include <drm/drm_drv.h>
 #include <drm/drm_print.h>
 
 void __drm_puts_coredump(struct drm_printer *p, const char *str)