drm/amd/display: Rename dcn_validate_bandwidth to dcn10_validate_bandwidth

[Why]
Rename function name so it aligns with other resource
function names being used by dcn10.

[How]
Rename function name for consistency.

Reviewed-by: Ahmad Othman <Ahmad.Othman@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Zhan Liu <Zhan.Liu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>