misc: microchip: pci1xxxx: Fix Kernel panic during IRQ handler registration

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

misc: microchip: pci1xxxx: Fix Kernel panic during IRQ handler registration

Resolve kernel panic while accessing IRQ handler associated with the

generated IRQ. This is done by acquiring the spinlock and storing the

current interrupt state before handling the interrupt request using

generic_handle_irq.

A previous fix patch was submitted where 'generic_handle_irq' was

replaced with 'handle_nested_irq'. However, this change also causes

the kernel panic where after determining which GPIO triggered the

interrupt and attempting to call handle_nested_irq with the mapped

IRQ number, leads to a failure in locating the registered handler.