ir3: Update .editorconfig and .dir-locals.el

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11801>

src/freedreno/ir3/.dir-locals.el

@@ -1,9 +1,9 @@
 ((prog-mode
-  (indent-tabs-mode . t)
-  (tab-width . 4)
-  (c-basic-offset . 4)
+  (indent-tabs-mode . nil)
+  (tab-width . 3)
+  (c-basic-offset . 3)
   (c-file-style . "k&r")
-  (fill-column . 78)
+  (fill-column . 80)
   (c-file-offsets
    (arglist-cont-nonempty . ++)
    )

src/freedreno/ir3/.editorconfig

@@ -1,5 +1,5 @@
 [*.{c,h,cpp,hpp,cc,hh}]
-indent_style = tab
-indent_size = 4
-tab_width = 4
-max_line_length = 78
+indent_style = space
+indent_size = 3
+tab_width = 3
+max_line_length = 80