ARC: update feature support for jump-labels

ARC jum-label support was added in 5.5rc1 but we missed updating the
feature list
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

Documentation/features/core/jump-labels/arch-support.txt

@@ -7,7 +7,7 @@
     |         arch |status|
     -----------------------
     |       alpha: | TODO |
-    |         arc: | TODO |
+    |         arc: |  ok  |
     |         arm: |  ok  |
     |       arm64: |  ok  |
     |         c6x: | TODO |