The clk_enable() call in the pm_clk_resume() call returns an error
that is not being checked. If clk_enable() fails then we should
not set the state of the clock to PCE_STATUS_ENABLED.

Note, the issue of warning the user if this fails has not been
addressed in this patch as this is not the only place the driver
calls clk_enable().
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
Reviewed-by: NIan Molton <ian.molton@codethink.co.uk>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>