drm/amd/display: Add DC Debug mask to disable features for bringup

[Why]
At bringup we want to be able to disable various power features.

[How]
These features are already exposed as dc_debug_options and exercised
on other OSes. Create a new dc_debug_mask module parameter and expose
relevant bits, in particular
 * DC_DISABLE_PIPE_SPLIT
 * DC_DISABLE_STUTTER
 * DC_DISABLE_DSC
 * DC_DISABLE_CLOCK_GATING

Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/include/amd_shared.h

@@ -150,6 +150,13 @@ enum DC_FEATURE_MASK {
 	DC_PSR_MASK = 0x8,
 };
 
+enum DC_DEBUG_MASK {
+	DC_DISABLE_PIPE_SPLIT = 0x1,
+	DC_DISABLE_STUTTER = 0x2,
+	DC_DISABLE_DSC = 0x4,
+	DC_DISABLE_CLOCK_GATING = 0x8
+};
+
 enum amd_dpm_forced_level;
 /**
  * struct amd_ip_funcs - general hooks for managing amdgpu IP Blocks