[Why]
I2C code did not match dc resource model and was generally
unpleasant

[How]
Move code into new svelte dce_i2c files, replacing various i2c
objects with two structs: dce_i2c_sw and dce_i2c_hw.  Fully split
sw and hw code paths.  Remove all redundant declarations.  Use
address lists to distinguish between versions.  Change dce80 code
to newer register access macros.
Signed-off-by: David Francis <David.Francis@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>