drm/radeon/dpm: add support for SVI2 voltage for SI

Some newer boards use SVI2 for voltage control rather
than GPIO.

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 60c47f8..d1592a0 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -317,6 +317,9 @@
 				  struct atom_voltage_table *voltage_table);
 bool radeon_atom_is_voltage_gpio(struct radeon_device *rdev,
 				 u8 voltage_type, u8 voltage_mode);
+int radeon_atom_get_svi2_info(struct radeon_device *rdev,
+			      u8 voltage_type,
+			      u8 *svd_gpio_id, u8 *svc_gpio_id);
 void radeon_atom_update_memory_dll(struct radeon_device *rdev,
 				   u32 mem_clock);
 void radeon_atom_set_ac_timing(struct radeon_device *rdev,