drm/radeon/trinity_dpm: fix a memleak in trinity_parse_power_table

The rdev->pm.dpm.ps allocated by kcalloc should be freed in every
following error-handling path. However, in the error-handling of
rdev->pm.power_state[i].clock_info the rdev->pm.dpm.ps is not freed,
resulting in a memleak in this function.

Fixes: d70229f7

 ("drm/radeon/kms: add dpm support for trinity asics")
Signed-off-by: Zhipeng Lu <alexious@zju.edu.cn>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>