drm/amdgpu: add UAPI to query GFX shadow sizes

Add UAPI to query the GFX shadow buffer requirements
for preemption on GFX11.  UMDs need to specify the shadow
areas for preemption.

v2: move into existing asic info query
    drop GDS as its use is determined by the UMD (Marek)
v3: Update comments to note that alignment is base
    virtual alignment (Alex)
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

include/uapi/drm/amdgpu_drm.h

@@ -1138,6 +1138,14 @@ struct drm_amdgpu_info_device {
 	__u64 mall_size;            /* AKA infinity cache */
 	/* high 32 bits of the rb pipes mask */
 	__u32 enabled_rb_pipes_mask_hi;
+	/* shadow area size for gfx11 */
+	__u32 shadow_size;
+	/* shadow area base virtual alignment for gfx11 */
+	__u32 shadow_alignment;
+	/* context save area size for gfx11 */
+	__u32 csa_size;
+	/* context save area base virtual alignment for gfx11 */
+	__u32 csa_alignment;
 };
 
 struct drm_amdgpu_info_hw_ip {