kirkwood-generic: update reason for BROKEN

The Linksys E4200 v2 uses mwl8k wifi, which does not support 11s.

targets/kirkwood-generic

 -- Linksys
 
 device('linksys-e4200-v2-viper', 'linksys_e4200-v2', {
-	broken = true, -- 802.11s untested
+	broken = true, -- no 802.11s support
 })

targets/targets.mk

@@ -29,6 +29,6 @@ $(eval $(call GluonTarget,x86,64))
 ifeq ($(BROKEN),1)
 $(eval $(call GluonTarget,bcm27xx,bcm2710)) # BROKEN: Untested
 $(eval $(call GluonTarget,bcm27xx,bcm2711)) # BROKEN: No 11s support, no reset button, sys LED issues
-$(eval $(call GluonTarget,kirkwood,generic)) # BROKEN: 11s support untested
+$(eval $(call GluonTarget,kirkwood,generic)) # BROKEN: No devices with 11s support
 $(eval $(call GluonTarget,mvebu,cortexa9)) # BROKEN: No 11s support
 endif