1. reverts commit e67f51012740 ("dc: temp disable DCC on high res.")
- default still DCC enabled

2. add debug options to decide how DCC is disabled
- disable DCC
- disable DCC if DCC requires 128b (aka. half) request
-- observed compressed data corruption result in screen corruption in
full (256b) request while half (128b) would cause DCN to hang, result in
DF hang
Signed-off-by: Tony Cheng <tony.cheng@amd.com>
Reviewed-by: Yongqiang Sun <yongqiang.sun@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>