drm/xe: Use FIELD_PREP/FIELD_GET for tile id encoding

Use FIELD_PREP()/FIELD_GET() to encode the tile id into flags. Besides
protecting for eventual overflow it also makes it easier to see a new
flag can't be added as BIT(7).

Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20230718193924.3084759-2-lucas.demarchi@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/xe/xe_vm_types.h

@@ -143,8 +143,8 @@ struct xe_vm {
 #define XE_VM_FLAG_SCRATCH_PAGE		BIT(4)
 #define XE_VM_FLAG_FAULT_MODE		BIT(5)
 #define XE_VM_FLAG_BANNED		BIT(6)
-#define XE_VM_FLAG_TILE_ID(flags)	(((flags) >> 7) & 0x3)
-#define XE_VM_FLAG_SET_TILE_ID(tile)	((tile)->id << 7)
+#define XE_VM_FLAG_TILE_ID(flags)	FIELD_GET(GENMASK(8, 7), flags)
+#define XE_VM_FLAG_SET_TILE_ID(tile)	FIELD_PREP(GENMASK(8, 7), (tile)->id)
 	unsigned long flags;
 
 	/** @composite_fence_ctx: context composite fence */