platform-drivers: x86: pmic: Use request_irq instead of chained handler

There is no need to install a chained handler for this hardware. This
is a plain x86 IOAPIC interrupt which is handled by the core code
perfectly fine. There is nothing special about demultiplexing these
gpio interrupts which justifies a custom hack. Replace it by a plain
old interrupt handler installed with request_irq. That makes the code
agnostic about the underlying primary interrupt hardware. The overhead
for this is minimal, but it gives us the advantage of accounting,
balancing and to detect interrupt storms. gpio interrupts are not
really that performance critical.

Patch fixups from akpm

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>