radeon_replay/radeon_util.h: Add macros for MIN and MAX
radeon_replay: Add preliminary AUX channel transaction handling

This gives us enough of a handler to be able to send and receive
messages via DisplayPort AUX channels.
radeon_replay: Add function to dump contents of an array
radeon_replay: Read DisplayPort configuration data on AUX 0

This uses AUX channel 0 to read the first 356 bytes of the DisplayPort
configuration data (DPCD), and dump the contents.
radeon_replay: Implement I²C transactions over AUX channel

This enables us to control I²C devices behind the DisplayPort sink,
such as EDID EEPROMs behind LVDS bridges.
radeon_replay: Read and dump EDID of device connected behind AUX0
radeon_replay: Add EDID decoder from coreboot