cpuidle: haltpoll: Do not enable interrupts when entering idle

The cpuidle drivers' ->enter() methods are supposed to be IRQ invariant:

  5e26aa93 ("cpuidle/poll: Ensure IRQs stay disabled after cpuidle_state::enter() calls")
  bb7b1125 ("cpuidle: Move IRQ state validation")

Do that in the haltpoll driver too.

Fixes: 5e26aa93

 ("cpuidle/poll: Ensure IRQs stay disabled after cpuidle_state::enter() calls")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218245
Reported-by:  <forza@tnonline.net>
Tested-by:  <forza@tnonline.net>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>