As pkg-config --variable doesn't respect the sysroot, add the pkg-config sysroot
to the beginning of variables that are used later on the host.

Upstream-Status: Pending
Signed-off-by: Ross Burton <ross.burton@intel.com>

diff --git a/configure.ac b/configure.ac
index 94da4f7..d29cd6a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -64,7 +64,7 @@ AC_SUBST(NEEDED)
 
 # Find the xcb-proto protocol descriptions
 AC_MSG_CHECKING(XCBPROTO_XCBINCLUDEDIR)
-XCBPROTO_XCBINCLUDEDIR=`$PKG_CONFIG --variable=xcbincludedir xcb-proto`
+XCBPROTO_XCBINCLUDEDIR=$PKG_CONFIG_SYSROOT_DIR/`$PKG_CONFIG --variable=xcbincludedir xcb-proto`
 AC_MSG_RESULT($XCBPROTO_XCBINCLUDEDIR)
 AC_SUBST(XCBPROTO_XCBINCLUDEDIR)
 
@@ -74,7 +74,7 @@ AC_SUBST(XCBPROTO_VERSION)
 
 # Find the xcbgen Python package
 AC_MSG_CHECKING(XCBPROTO_XCBPYTHONDIR)
-XCBPROTO_XCBPYTHONDIR=`$PKG_CONFIG --variable=pythondir xcb-proto`
+XCBPROTO_XCBPYTHONDIR=$PKG_CONFIG_SYSROOT_DIR/`$PKG_CONFIG --variable=pythondir xcb-proto`
 AC_MSG_RESULT($XCBPROTO_XCBPYTHONDIR)
 AC_SUBST(XCBPROTO_XCBPYTHONDIR)