drm/amdgpu/gfx9: enable cp interrupt for CGCG/CGLS/MGCG

Required for proper handshaking between the GFX and RLC.
Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c

@@ -1460,9 +1460,6 @@ static void gfx_v9_0_enable_gui_idle_interrupt(struct amdgpu_device *adev,
 {
 	u32 tmp = RREG32_SOC15(GC, 0, mmCP_INT_CNTL_RING0);
 
-	if (enable)
-		return;
-
 	tmp = REG_SET_FIELD(tmp, CP_INT_CNTL_RING0, CNTX_BUSY_INT_ENABLE, enable ? 1 : 0);
 	tmp = REG_SET_FIELD(tmp, CP_INT_CNTL_RING0, CNTX_EMPTY_INT_ENABLE, enable ? 1 : 0);
 	tmp = REG_SET_FIELD(tmp, CP_INT_CNTL_RING0, CMP_BUSY_INT_ENABLE, enable ? 1 : 0);