tools: add pkg-config file for libxc

When configuring the build of qemu the configure script is building
various test programs to determine the exact version of libxencontrol.

Instead of a try and error approach needing updates for nearly each
new version of Xen just provide xencontrol.pc to be used via
pkg-config.

In the end we need two different variants of that file: one for the
target system where eventually someone wants to build qemu, and one
for the local system to be used for building qemu as part of the Xen
build process.

The local variant is created in a dedicated directory in order to be
able to collect more pkg-config files used for building tools there.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>

.gitignore

@@ -79,6 +79,7 @@ stubdom/newlib-1.*
 stubdom/newlib-x86*
 stubdom/ocaml-*
 stubdom/pciutils-*
+stubdom/pkg-config/*
 stubdom/polarssl-*
 stubdom/stubdompath.sh
 stubdom/tpm_emulator-*
@@ -179,6 +180,7 @@ tools/include/xen/*
 tools/include/xen-xsm/*
 tools/include/xen-foreign/*.(c|h|size)
 tools/include/xen-foreign/checker
+tools/libxc/*.pc
 tools/libxl/_libxl.api-for-check
 tools/libxl/*.api-ok
 tools/libxl/*.pc
@@ -204,6 +206,7 @@ tools/misc/xen-hvmctx
 tools/misc/xenlockprof
 tools/misc/lowmemd
 tools/misc/xencov
+tools/pkg-config/*
 tools/xentrace/xenalyze
 tools/pygrub/build/*
 tools/python/build/*