bcm63xx: fix description fix name case

The `Description` should be capital.

Signed-off-by: Huangbin Zhan <[email protected]>

target/linux/bcm63xx/profiles/default.mk

@@ -8,7 +8,7 @@ define Profile/Default
   PRIORITY:=1
 endef
 
-define Profile/Default/description
+define Profile/Default/Description
   Package set compatible with most boards.
 endef