Revert "drm/radeon/pm: autoswitch power state when in balanced mode"

This reverts commit 1c331f75

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Breaks resume on some systems.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=100759
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org