blorp: Add a blorp_address::local_hint flag

This will be used as a performance hint for XY_BLOCK_COPY_BLT to
indicate whether the source/destination surfaces are (likely) in
device-local memory or system memory.  We don't need to be precise
here - it's okay to set the fields to LOCAL even if a buffer has
been evicted out to system memory.

We should set this from Vulkan too, but I haven't yet.  There isn't
a convenient anv_bo field like there is in iris...

Reviewed-by: Caio Oliveira <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14687>

src/intel/blorp/blorp.h

@@ -106,6 +106,13 @@ struct blorp_address {
    uint64_t offset;
    unsigned reloc_flags;
    uint32_t mocs;
+
+   /**
+    * True if this buffer is intended to live in device-local memory.
+    * This is only a performance hint; it's OK to set it to true even
+    * if eviction has temporarily forced the buffer to system memory.
+    */
+   bool local_hint;
 };
 
 struct blorp_surf