apr: fix LTFLAGS to make it work with ccache

When ccache is enabled, libtool requires --tag=CC when use ccache,
otherwise when building apr-util with ccache enabled:

| libtool: compile: unable to infer tagged configuration
| libtool: error: specify a tag with '--tag'
| libtool: compile: unable to infer tagged configuration
| make[1]: *** [buckets/apr_buckets.lo] Error 1

(From OE-Core rev: 52c314963e0ab90e6c1ced7bf66b06d4c304358a)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-support/apr/apr/configure.in-fix-LTFLAGS-to-make-it-work-with-ccache.patch

@@ -0,0 +1,36 @@
+From d439093aa07a486f559206ac9e5808a6a18218cd Mon Sep 17 00:00:00 2001
+From: Robert Yang <liezhi.yang@windriver.com>
+Date: Thu, 19 Nov 2015 18:25:38 -0800
+Subject: [PATCH] configure.in: fix LTFLAGS to make it work with ccache
+
+When ccache is enabled, libtool requires --tag=CC when use ccache,
+otherwise when building apr-util with ccache enabled:
+
+| libtool: compile: unable to infer tagged configuration
+| libtool: error: specify a tag with '--tag'
+| libtool: compile: unable to infer tagged configuration
+| make[1]: *** [buckets/apr_buckets.lo] Error 1
+
+Upstream-Status: Pending
+
+Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
+---
+ configure.in |    2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/configure.in b/configure.in
+index 5a4a988..9d57ae6 100644
+--- a/configure.in
++++ b/configure.in
+@@ -246,7 +246,7 @@ case $host in
+     ;;
+ *)
+     if test "x$LTFLAGS" = "x"; then
+-        LTFLAGS='--silent'
++        LTFLAGS='--silent --tag=CC'
+     fi
+     if test "$experimental_libtool" = "yes"; then
+         # Use a custom-made libtool replacement
+-- 
+1.7.9.5
+

meta/recipes-support/apr/apr_1.5.2.bb

@@ -16,6 +16,7 @@ SRC_URI = "${APACHE_MIRROR}/apr/${BPN}-${PV}.tar.bz2 \
            file://run-ptest \
            file://upgrade-and-fix-1.5.1.patch \
            file://Fix-packet-discards-HTTP-redirect.patch \
+           file://configure.in-fix-LTFLAGS-to-make-it-work-with-ccache.patch \
 "
 
 SRC_URI[md5sum] = "4e9769f3349fe11fc0a5e1b224c236aa"