cogl/cogl-renderer.c: Avoid Clash with Newer Windows SDKs

The DriverCallback is a function that is defined by the Windows SDK 8.0+
headers, which was initially used for device driver development.  The use
of DriverCallback would cause a clash, causing things to break when built
with newer Windows SDKs, so rename DriverCallback to CoglDriverCallback to
avoid this problem.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit 001cffd783cfcce9f68bd976891f11760b2f89cc)
cogl-pango-pipeline-cache.c: Include forgotten header

The private header is needed as the cogl_texture_get_format API was made
private, so that C4013 (implicit declaration of ...) warnings/errors can
be avoided

Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit bb10532f4b11cba169ace6d9e26543fe6f70ad8f)