This commit moves ISA-specific code to separate function and makes that
function depend on CONFIG_{E}ISA so that we do not have to maintain
acpi_isa_irq_to_gsi() function for architectures which do not support ISA.
Signed-off-by: NTomasz Nowicki <tomasz.nowicki@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>