power: supply: pm8916_lbc: Fix use-after-free for extcon in IRQ handler

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

power: supply: pm8916_lbc: Fix use-after-free for extcon in IRQ handler

Using the `devm_` variant for requesting IRQ _before_ the `devm_`

variant for allocating/registering the `extcon` handle, means that the

`extcon` handle will be deallocated/unregistered _before_ the interrupt

handler (since `devm_` naturally deallocates in reverse allocation

order). This means that during removal, there is a race condition where

an interrupt can fire just _after_ the `extcon` handle has been

freed, *but* just _before_ the corresponding unregistration of the IRQ

handler has run.

This will lead to the IRQ handler calling `extcon_set_state_sync()` with

a freed `extcon` handle. Which usually crashes the system or otherwise

silently corrupts the memory...

Fix this racy use-after-free by making sure the IRQ is requested _after_

the registration of the `extcon` handle.