Define PKG_CONFIG_PATH when building for desktop on UNIX.

toolchains/toolchain-desktop.cmake

@@ -20,4 +20,9 @@
 #
 ############################################################################
 
-# Default toolchain, use native environment. Nothing to be done.
+# Default toolchain, use native environment.
+
+# Adjust PKG_CONFIG_PATH to include install directory
+if(UNIX)
+	set(LINPHONE_BUILDER_PKG_CONFIG_PATH "${CMAKE_INSTALL_PREFIX}/lib/pkgconfig/:$ENV{PKG_CONFIG_PATH}:/usr/lib/pkgconfig/:/usr/lib/x86_64-linux-gnu/pkgconfig/:/usr/share/pkgconfig/:/usr/local/lib/pkgconfig/:/opt/local/lib/pkgconfig/")
+endif(UNIX)