drm/radeon: add atom get leakage vddc function

Required for DPM on SI.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index be79a4d..706b018 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -233,6 +233,9 @@
 				 u8 voltage_type, u16 *voltage_step);
 int radeon_atom_get_max_vddc(struct radeon_device *rdev, u8 voltage_type,
 			     u16 voltage_id, u16 *voltage);
+int radeon_atom_get_leakage_vddc_based_on_leakage_idx(struct radeon_device *rdev,
+						      u16 *voltage,
+						      u16 leakage_idx);
 int radeon_atom_round_to_true_voltage(struct radeon_device *rdev,
 				      u8 voltage_type,
 				      u16 nominal_voltage,
diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c
index 830c558..0ac7294 100644
--- a/drivers/gpu/drm/radeon/radeon_atombios.c
+++ b/drivers/gpu/drm/radeon/radeon_atombios.c
@@ -3062,6 +3062,13 @@
 	return 0;
 }
 
+int radeon_atom_get_leakage_vddc_based_on_leakage_idx(struct radeon_device *rdev,
+						      u16 *voltage,
+						      u16 leakage_idx)
+{
+	return radeon_atom_get_max_vddc(rdev, VOLTAGE_TYPE_VDDC, leakage_idx, voltage);
+}
+
 int radeon_atom_get_voltage_gpio_settings(struct radeon_device *rdev,
 					  u16 voltage_level, u8 voltage_type,
 					  u32 *gpio_value, u32 *gpio_mask)