[gtk+] Tell gtk-doc to ignore private headers

[Matthias Clasen <matthiasc src gnome org>]

commit 8bd9604fe6afac5b3a9129fffe20984ffd22301a
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Jun 20 10:47:18 2015 -0400

    Tell gtk-doc to ignore private headers
    
    Tell gtk-doc to ignore new private headers as well, otherwise
    it complains about undocumented symbols in them.

 docs/reference/gtk/Makefile.am |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/docs/reference/gtk/Makefile.am b/docs/reference/gtk/Makefile.am
index 7e7cd5a..fcb34b0 100644
--- a/docs/reference/gtk/Makefile.am
+++ b/docs/reference/gtk/Makefile.am
@@ -129,6 +129,7 @@ IGNORE_HFILES = \
        gtkmountoperationprivate.h      \
        gtkorientableprivate.h          \
        gtkpixelcacheprivate.h          \
+       gtkplacessidebarprivate.h       \
        gtkpopoverprivate.h             \
        gtkprinter-private.h            \
        gtkprintoperation-private.h     \
@@ -144,6 +145,7 @@ IGNORE_HFILES = \
        gtksearchentryprivate.h         \
        gtkselectionprivate.h           \
        gtksettingsprivate.h            \
+       gtksidebarrowprivate.h          \
        gtksizegroup-private.h          \
        gtksizerequestcacheprivate.h    \
        gtksocketprivate.h              \