drm/amd/display: clkmgr unittest with removal of warn & rename DCN35 ips handshake...

drm/amd/display: clkmgr unittest with removal of warn & rename DCN35 ips handshake for idle

[why]
To Remove warnings of clk_mgr.

[How]
Added code to remove warnings by resolving redefinations.

Reviewed-by: Martin Leung <martin.leung@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Mounika Adhuri <moadhuri@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>