configure: set HAVE_COMMON_DRI when building only swrast

configure: set HAVE_COMMON_DRI when building only swrast

With commit cb1febb07, I have incorrectly removed HAVE_COMMON_DRI
assuming that swrast does not need to build the translations for
driconf options, as effectively swrast/drisw does not use them.

With the incoming unification work of dri and drisw, it makes
sense just to revert the offending hunk.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=70057
Reported-by: Vinson Lee <vlee@freedesktop.org>
Tested-by: Vinson Lee <vlee@freedesktop.org>
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>