Implement code to set/get lpmode for as9716-32d platform
Co-authored-by: Jostar Yang <jostar_yang@accton.com.tw>
Modify get_psu_presence(). Move read() and close() to "try: ... except IOError:" To avoid when read port present sysfs fail. This exception will let sfputil.py to exit. So "sfputil show eeprom" can't show other port status.
