Make DRI dependencies and build depend on the target

Make DRI dependencies and build depend on the target

- Don't require xcb-dri[23] etc. if we aren't building for a target with DRM, as
we won't be using dri[23]

- Enable a more fine-grained control of what DRI code is built, so that a libGL
using direct swrast can be built on targets which don't have DRM.

The HAVE_DRI automake conditional is retired in favour of a number of other
conditionals:

HAVE_DRI2 enables building of code using the DRI2 interface (and possibly DRI3
with HAVE_DRI3)

HAVE_DRISW enables building of DRI swrast

HAVE_DRICOMMON enables building of target-independent DRI code, and also enables
some makefile cases where a more detailled decision is made at a lower level.

HAVE_APPLEDRI enables building of an Apple-specific direct rendering interface,
still which requires additional fixing up to build properly.

v2:
Place xfont.c and drisw_glx.c into correct categories.
Update 'make check' as well

Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>
Reviewed-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>