arch: linker: specify intList section in the IDT_LIST region

This commit specifies the intList section in the IDT_LIST region in the
arch/common CMakeLists.txt file.

It uses zephyr_linker_section to setup the intList section for first
pass linker file and configures the section to hold irq_info and
intList input section.

For second pass linker file, the irq_info and intList input sections are
placed in the /DISCARD/ section.

Signed-off-by: Torsten Rasmussen <Torsten.Rasmussen@nordicsemi.no>