regulator: tps65219: fix irq_data.rdev not being assigned

In the Linux kernel, the following vulnerability has been resolved:

regulator: tps65219: fix irq_data.rdev not being assigned

Commit 64a6b577490c ("regulator: tps65219: Remove debugging helper
function") removed the tps65219_get_rdev_by_name() helper along with
the irq_data.rdev assignment that depended on it. This left
irq_data.rdev uninitialized for all IRQs, causing undefined behavior
when regulator_notifier_call_chain() is called from the IRQ handler:

Internal error: Oops: 0000000096000004
pc : regulator_notifier_call_chain
lr : tps65219_regulator_irq_handler
Call trace:
regulator_notifier_call_chain
tps65219_regulator_irq_handler
handle_nested_irq
regmap_irq_thread
irq_thread_fn
irq_thread
kthread
ret_from_fork

Instead of restoring a dedicated lookup array, restructure the probe
function to combine regulator registration with IRQ registration in
the same loop. This way the rdev returned by devm_regulator_register()
is naturally available for assigning to irq_data.rdev without any
auxiliary data structure.

Non-regulator IRQs (SENSOR, TIMEOUT) that don't correspond to any
registered regulator are registered with rdev=NULL, and the IRQ handler
is protected with a NULL check to avoid crashing.