drm implemenation used by the PowerVR Kyro drivers.

Based on the XFree86 4.1.0 drm headers with modifications
to add additional hooks into the drm module.  Modified files
are prefixed with "pvr_" and the new code is surrounded by

/* BEGIN IMGTEC MODIFICATION */       
/* END IMGTEC MODIFICATION */

Exception: drmP.h is only tagged and not renamed, as all
references to it would also need to be modified.