drm/radeon/dpm: implement force performance levels for 7xx/eg/btc

Allows you to limit the selected power levels via sysfs.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/radeon_asic.c b/drivers/gpu/drm/radeon/radeon_asic.c
index a5b244d..221a0b3 100644
--- a/drivers/gpu/drm/radeon/radeon_asic.c
+++ b/drivers/gpu/drm/radeon/radeon_asic.c
@@ -1393,6 +1393,7 @@
 		.get_mclk = &rv770_dpm_get_mclk,
 		.print_power_state = &rv770_dpm_print_power_state,
 		.debugfs_print_current_performance_level = &rv770_dpm_debugfs_print_current_performance_level,
+		.force_performance_level = &rv770_dpm_force_performance_level,
 	},
 	.pflip = {
 		.pre_page_flip = &rs600_pre_page_flip,
@@ -1516,6 +1517,7 @@
 		.get_mclk = &rv770_dpm_get_mclk,
 		.print_power_state = &rv770_dpm_print_power_state,
 		.debugfs_print_current_performance_level = &rv770_dpm_debugfs_print_current_performance_level,
+		.force_performance_level = &rv770_dpm_force_performance_level,
 	},
 	.pflip = {
 		.pre_page_flip = &evergreen_pre_page_flip,
@@ -1762,6 +1764,7 @@
 		.get_mclk = &btc_dpm_get_mclk,
 		.print_power_state = &rv770_dpm_print_power_state,
 		.debugfs_print_current_performance_level = &rv770_dpm_debugfs_print_current_performance_level,
+		.force_performance_level = &rv770_dpm_force_performance_level,
 	},
 	.pflip = {
 		.pre_page_flip = &evergreen_pre_page_flip,