SPM: Add IRQ data in Partition Loading

This patch:
 - Adds IRQ load data structure
 - Moves IRQ data into Partition load info
 - Moves Interrupt initialization from main() to load api
 - Updates get_irq_line_for_signal() accordingly
 - Moves tfm_irq_list.h to Library Model as it is not used by IPC

Change-Id: I4945e24bd977ef3d3e472bc58dfa618c3fb2d706
Signed-off-by: Kevin Peng <kevin.peng@arm.com>