drm/amdgpu: Add DCC flags for GFX9 amdgpu_bo

[Why]
Hardware support for Delta Color Compression (DCC) decompression is
available in DC for GFX9 but there's no way for userspace to enable
the feature.

Enabling the feature can provide improved GFX performance and
power savings in many situations.

[How]
Extend the GFX9 tiling flags to include DCC parameters. These are
logically grouped together with tiling flags even if they are
technically distinct.

This trivially maintains backwards compatibility with existing
users of amdgpu_gem_metadata. No new IOCTls or data structures are
needed to support DCC.

This patch helps expose DCC attributes to both libdrm and amdgpu_dm.

Signed-off-by: Nicholas Kazlauskas <[e-mail]>
Reviewed-by: Marek Olšák <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

include/uapi/drm/amdgpu_drm.h

···
 /* GFX9 and later: */
 #define AMDGPU_TILING_SWIZZLE_MODE_SHIFT		0
 #define AMDGPU_TILING_SWIZZLE_MODE_MASK			0x1f
+#define AMDGPU_TILING_DCC_OFFSET_256B_SHIFT		5
+#define AMDGPU_TILING_DCC_OFFSET_256B_MASK		0xFFFFFF
+#define AMDGPU_TILING_DCC_PITCH_MAX_SHIFT		29
+#define AMDGPU_TILING_DCC_PITCH_MAX_MASK		0x3FFF
+#define AMDGPU_TILING_DCC_INDEPENDENT_64B_SHIFT		43
+#define AMDGPU_TILING_DCC_INDEPENDENT_64B_MASK		0x1
 
 /* Set/Get helpers for tiling flags. */
 #define AMDGPU_TILING_SET(field, value) \