drm/radeon: switch get_gpu_clock() to a callback (v2)

Cleans up the code for future asics

v2: rebase, fix some missing radeon_asic updates

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index 37d81fd..6d4b561 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -4461,14 +4461,14 @@
 }
 
 /**
- * r600_get_gpu_clock - return GPU clock counter snapshot
+ * r600_get_gpu_clock_counter - return GPU clock counter snapshot
  *
  * @rdev: radeon_device pointer
  *
  * Fetches a GPU clock counter snapshot (R6xx-cayman).
  * Returns the 64 bit clock counter snapshot.
  */
-uint64_t r600_get_gpu_clock(struct radeon_device *rdev)
+uint64_t r600_get_gpu_clock_counter(struct radeon_device *rdev)
 {
 	uint64_t clock;