uboot-phytec

dm: x86: Add a common PIRQ init function

Most x86 interrupt drivers will want to use the standard PIRQ routing and
table setup. Put this code in a common function so it can be used by those
drivers that want it.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>