v2: prefer seq_puts to seq_printf detected by Paulo Zanoni.
v3: PSR is disabled by default. Without userspace ready it
    will cause regression for kde and xdm users
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Reviewed-by: Shobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>