drm/amd: fix gfx hang on renoir in IGT reload test

[why]
CP hangs in igt reloading test on renoir, more precisely, hangs on the
second time insmod.

[how]
mode2 reset can make it recover, and mode2 reset only effects gfx core,
dcn and the screen will not be impacted.
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Tianci.Yin <tianci.yin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/soc15.c

@@ -853,6 +853,10 @@ static bool soc15_need_reset_on_init(struct amdgpu_device *adev)
 {
 	u32 sol_reg;
 
+	/* CP hangs in IGT reloading test on RN, reset to WA */
+	if (adev->asic_type == CHIP_RENOIR)
+		return true;
+
 	/* Just return false for soc15 GPUs.  Reset does not seem to
 	 * be necessary.
 	 */