Linux: Initialize IRQ handling in libmetal initialization
Linux: Initialize IRQ handling in libmetal initialization

When doing the libmetal Linux initialization, initialize
interrupts handling, which is to start the interrupt mornitoring
thread. When shutting down the Linux libmetal, shut down interrupts
handling, which is to stop the interrupt mornitorying thread.

Signed-off-by: Wendy Liang <cac46fad14f88489ab4dbc3c1082c7dafae20187@xilinx.com>

forg0ne/libmetal,forg0ne/libmetal