drm/amdgpu: fix scratch register access method in SRIOV

The scratch register should be accessed through MMIO instead of RLCG
in SRIOV, since it being used in RLCG register access function.

Fixes: d54762cc ("drm/amdgpu: nuke dynamic gfx scratch reg allocation")
Signed-off-by: ZhenGuo Yin <zhenguo.yin@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c

@@ -3780,11 +3780,12 @@ static void gfx_v10_0_wait_reg_mem(struct amdgpu_ring *ring, int eng_sel,
 static int gfx_v10_0_ring_test_ring(struct amdgpu_ring *ring)
 {
 	struct amdgpu_device *adev = ring->adev;
+	uint32_t scratch = SOC15_REG_OFFSET(GC, 0, mmSCRATCH_REG0);
 	uint32_t tmp = 0;
 	unsigned i;
 	int r;
 
-	WREG32_SOC15(GC, 0, mmSCRATCH_REG0, 0xCAFEDEAD);
+	WREG32(scratch, 0xCAFEDEAD);
 	r = amdgpu_ring_alloc(ring, 3);
 	if (r) {
 		DRM_ERROR("amdgpu: cp failed to lock ring %d (%d).\n",
@@ -3793,13 +3794,13 @@ static int gfx_v10_0_ring_test_ring(struct amdgpu_ring *ring)
 	}
 
 	amdgpu_ring_write(ring, PACKET3(PACKET3_SET_UCONFIG_REG, 1));
-	amdgpu_ring_write(ring, SOC15_REG_OFFSET(GC, 0, mmSCRATCH_REG0) -
+	amdgpu_ring_write(ring, scratch -
 			  PACKET3_SET_UCONFIG_REG_START);
 	amdgpu_ring_write(ring, 0xDEADBEEF);
 	amdgpu_ring_commit(ring);
 
 	for (i = 0; i < adev->usec_timeout; i++) {
-		tmp = RREG32_SOC15(GC, 0, mmSCRATCH_REG0);
+		tmp = RREG32(scratch);
 		if (tmp == 0xDEADBEEF)
 			break;
 		if (amdgpu_emu_mode == 1)