drm/amdgpu: use read-modify-write mode for gfx v9_4_3 SQ setting

Instead of using direct update, avoid touching unrelated fields.

Signed-off-by: Tao Zhou <tao.zhou1@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Author: Tao Zhou

drivers/gpu/drm/amd/amdgpu/gfx_v9_4_3.c

@@ -4042,7 +4042,8 @@ static void gfx_v9_4_3_inst_enable_watchdog_timer(struct amdgpu_device *adev,
 	uint32_t i;
 	uint32_t data;
 
-	data = REG_SET_FIELD(0, SQ_TIMEOUT_CONFIG, TIMEOUT_FATAL_DISABLE,
+	data = RREG32_SOC15(GC, GET_INST(GC, 0), regSQ_TIMEOUT_CONFIG);
+	data = REG_SET_FIELD(data, SQ_TIMEOUT_CONFIG, TIMEOUT_FATAL_DISABLE,
 			     amdgpu_watchdog_timer.timeout_fatal_disable ? 1 : 0);
 
 	if (amdgpu_watchdog_timer.timeout_fatal_disable &&