drm: Make drm_clflush_virt_range() void*

Currently drm_cflush_virt_rage() takes a char* so the caller probably
has to do pointless casting to avoid compiler warnings. Make the
argument void* instead to avoid such issues.

v2: Use void* arithmetic (Chris)

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index daac00a..150780b 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1322,7 +1322,7 @@
 /* Cache management (drm_cache.c) */
 void drm_clflush_pages(struct page *pages[], unsigned long num_pages);
 void drm_clflush_sg(struct sg_table *st);
-void drm_clflush_virt_range(char *addr, unsigned long length);
+void drm_clflush_virt_range(void *addr, unsigned long length);
 
 				/* Locking IOCTL support (drm_lock.h) */
 extern int drm_lock(struct drm_device *dev, void *data,