swr: [rasterizer] add a .dir-locals.el to support 4-space indents

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Tim Rowley <timothy.o.rowley@intel.com>

src/gallium/drivers/swr/rasterizer/.dir-locals.el

@@ -0,0 +1,8 @@
+((prog-mode
+  (c-basic-offset . 4)
+  (c-file-style . "k&r")
+  (fill-column . 78)
+  (indent-tabs-mode . nil)
+  (show-trailing-whitespace . t)
+  )
+ )