Doing RCU-idle outside the driver, only to then temporarily enable it
again before going idle is suboptimal.

Notably: this converts all dt_init_idle_driver() and
__CPU_PM_CPU_IDLE_ENTER() users for they are inextrably intertwined.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
Tested-by: NTony Lindgren <tony@atomide.com>
Tested-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NFrederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195540.068981667@infradead.org