drm/radeon/radeon_drv: Move prototypes to a shared headerfile

Fixes the following W=1 kernel build warning(s):

 62 | void radeon_driver_unload_kms(struct drm_device *dev)
 | ^~~~~~~~~~~~~~~~~~~~~~~~
 drivers/gpu/drm/radeon/radeon_kms.c:105:5: warning: no previous prototype for ‘radeon_driver_load_kms’ [-Wmissing-prototypes]
 105 | int radeon_driver_load_kms(struct drm_device *dev, unsigned long flags)
 | ^~~~~~~~~~~~~~~~~~~~~~
 drivers/gpu/drm/radeon/radeon_kms.c:619:6: warning: no previous prototype for ‘radeon_driver_lastclose_kms’ [-Wmissing-prototypes]
 619 | void radeon_driver_lastclose_kms(struct drm_device *dev)
 | ^~~~~~~~~~~~~~~~~~~~~~~~~~~
 drivers/gpu/drm/radeon/radeon_kms.c:634:5: warning: no previous prototype for ‘radeon_driver_open_kms’ [-Wmissing-prototypes]
 634 | int radeon_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv)
 | ^~~~~~~~~~~~~~~~~~~~~~
 drivers/gpu/drm/radeon/radeon_kms.c:705:6: warning: no previous prototype for ‘radeon_driver_postclose_kms’ [-Wmissing-prototypes]
 705 | void radeon_driver_postclose_kms(struct drm_device *dev,
 | ^~~~~~~~~~~~~~~~~~~~~~~~~~~

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Gareth Hughes <gareth@valinux.com>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/radeon_drv.c

@@ -111,12 +111,6 @@
 #define KMS_DRIVER_MAJOR	2
 #define KMS_DRIVER_MINOR	50
 #define KMS_DRIVER_PATCHLEVEL	0
-int radeon_driver_load_kms(struct drm_device *dev, unsigned long flags);
-void radeon_driver_unload_kms(struct drm_device *dev);
-void radeon_driver_lastclose_kms(struct drm_device *dev);
-int radeon_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv);
-void radeon_driver_postclose_kms(struct drm_device *dev,
-				 struct drm_file *file_priv);
 int radeon_suspend_kms(struct drm_device *dev, bool suspend,
 		       bool fbcon, bool freeze);
 int radeon_resume_kms(struct drm_device *dev, bool resume, bool fbcon);

drivers/gpu/drm/radeon/radeon_drv.h

@@ -118,4 +118,11 @@
 long radeon_drm_ioctl(struct file *filp,
 		      unsigned int cmd, unsigned long arg);
 
+int radeon_driver_load_kms(struct drm_device *dev, unsigned long flags);
+void radeon_driver_unload_kms(struct drm_device *dev);
+void radeon_driver_lastclose_kms(struct drm_device *dev);
+int radeon_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv);
+void radeon_driver_postclose_kms(struct drm_device *dev,
+				 struct drm_file *file_priv);
+
 #endif				/* __RADEON_DRV_H__ */