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

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.

Fixes: 194f9f94a516 ("misc: microchip: pci1xxxx: Resolve kernel panic during GPIO IRQ handling")
Cc: stable <stable@kernel.org>
Signed-off-by: Rengarajan S <rengarajan.s@microchip.com>
Link: https://lore.kernel.org/r/20250313170856.20868-2-rengarajan.s@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>