radeon: Hack up an implementation of MapBufferRange

This doesn't implement any of the "cool" features of MapBufferRange.
Adding this function is necessary for the next commit in the series.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Acked-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
Cc: Maciej Cencora <m.cencora@gmail.com>
1 file changed