write_large_scale_tile_obu: fix implicit conv warning

w/clang -fsanitize=integer quiets warning of the form:
implicit conversion from type 'uint32_t' (aka 'unsigned int') of value
2164260864 (32-bit, unsigned) to type 'int' changed the value to
-2130706432 (32-bit, signed)

Bug: aomedia:3136
Bug: b/229626362
Change-Id: I62727f392e85fdbdb675ed4a78d5e7668bf78796
diff --git a/av1/encoder/bitstream.c b/av1/encoder/bitstream.c
index 6e4af81..a7d3254 100644
--- a/av1/encoder/bitstream.c
+++ b/av1/encoder/bitstream.c
@@ -3602,7 +3602,7 @@
           }
         }
 
-        mem_put_le32(buf->data, tile_header);
+        mem_put_le32(buf->data, (MEM_VALUE_T)tile_header);
       }
 
       *total_size += tile_size;