drm/amdgpu/gmc10: remove dead code

Leftover from bring up.  We look up the actual pre-OS memory usage
value later in the same function.
Reviewed-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c

@@ -736,15 +736,6 @@ static int gmc_v10_0_sw_init(void *handle)
 	 */
 	adev->gmc.mc_mask = 0xffffffffffffULL; /* 48 bit MC */
 
-	/*
-	 * Reserve 8M stolen memory for navi10 like vega10
-	 * TODO: will check if it's really needed on asic.
-	 */
-	if (amdgpu_emu_mode == 1)
-		adev->gmc.stolen_size = 0;
-	else
-		adev->gmc.stolen_size = 9 * 1024 *1024;
-
 	r = dma_set_mask_and_coherent(adev->dev, DMA_BIT_MASK(44));
 	if (r) {
 		printk(KERN_WARNING "amdgpu: No suitable DMA available.\n");