serial: 8250: Change console_msr_work to IRQ_WORK_LAZY

Change console_msr_work (defers MSR handling) to be IRQ_WORK_LAZY,
thus not raising an IRQ upon irq_work queueing. The irq_work is then
handled on the next kernel tick. This additional delay is acceptable
because any pending MSR handling is also performed in the interrupt
handler, if mctrl is queried, and during console resume. Using
IRQ_WORK_LAZY has the benefit of not needing to raise an IRQ for
each line of atomic console printing when modem control is active.

On a side note, the Tegra20 and Tegra30 platforms can hang if an
irq_work IRQ is raised while entering cpuidle states. This problem
was reproducible by performing atomic printing while entering cpuidle.
So this change also provides a workaround for these platforms (as
long as they are not running tickless). The discussion on this topic
is linked below.

Link: https://lore.kernel.org/lkml/f3757a75-0ba1-4558-bf57-f19ab7e59a4c@nvidia.com
Fixes: d3539347022a ("serial: 8250: Switch to nbcon console, take 2")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://patch.msgid.link/20260921143939.170314-1-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>