PNP / ACPI: use u8 instead of int in acpi_resource_extended_irq context

acpi_resource_extented_irq variables are all u8.
Use that type for triggering, polarity and shareable.
This fixes gcc warnings of type
"conversion to u8 from int may alter its value"

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>