manual: Fix BR2_GLOBAL_PATCH_DIR example

As discussed on irc, there is a missing part in the BR2_GLOBAL_PATCH_DIR
    example compared to the ASCII figure under customize-packages section.

Signed-off-by: Sebastien Roy <sebastien.roy@savoirfairelinux.com>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

docs/manual/customize-packages.txt

@@ -86,7 +86,7 @@ If the user has the +BR2_GLOBAL_PATCH_DIR+ configuration option set as
 follows:
 
 -----
-BR2_GLOBAL_PATCH_DIR="board/common-fooarch board/fooarch-board"
+BR2_GLOBAL_PATCH_DIR="board/common-fooarch/patches board/fooarch-board/patches"
 -----
 
 Then the patches would applied as follows for the Linux kernel: