ftdi_ft4222: Refactoring of I/O expander support.
ftdi_ft4222: Refactoring of I/O expander support.

Refactored of I/O expander support to simplify addition of new devices.
This had added ISR support for PCA9555.

Signed-off-by: Henry Bruce <57ea958cad66de244404958c9a01f7a4ad51b29e@intel.com>
Signed-off-by: Brendan Le Foll <3e0e8c4069934e8b47d99704927a85c66c0ceb33@intel.com>

ncrastanaren/mraa,w4ilun/mraa,jontrulson/mraa,alext-mkrs/mraa,stefan-andritoiu/mraa,stefan-andritoiu/mraa,Propanu/mraa,KurtE/mraa,stefan-andritoiu/mraa-gpio-chardev,g-vidal/mraa,Hbrinj/mraa,whbruce/mraa,Propanu/mraa,arfoll/mraa,Hbrinj/mraa,Pillar1989/mraa,ProfFan/mraa,sergev/mraa,arfoll/mraa,ncrastanaren/mraa,arunlee77/mraa,alext-mkrs/mraa,sergev/mraa,spitfire88/mraa,alext-mkrs/mraa,arunlee77/mraa,intel-iot-devkit/mraa,petreeftime/mraa,w4ilun/mraa,arfoll/mraa,petreeftime/mraa,Jon-ICS/mraa,g-vidal/mraa,intel-iot-devkit/mraa,malikabhi05/mraa,ncrastanaren/mraa,malikabhi05/mraa,sergev/mraa,ncrastanaren/mraa,andreivasiliu2211/mraa,g-vidal/mraa,whbruce/mraa,arfoll/mraa,intel-iot-devkit/mraa,jontrulson/mraa,Propanu/mraa,arfoll/mraa,Jon-ICS/mraa,Pillar1989/mraa,g-vidal/mraa,yongli3/mraa,andreivasiliu2211/mraa,stefan-andritoiu/mraa-gpio-chardev,malikabhi05/mraa,ncrastanaren/mraa,andreivasiliu2211/mraa,spitfire88/mraa,Jon-ICS/mraa,yongli3/mraa,KurtE/mraa,stefan-andritoiu/mraa,ProfFan/mraa,KurtE/mraa,spitfire88/mraa,stefan-andritoiu/mraa,arunlee77/mraa,Propanu/mraa,arunlee77/mraa,yongli3/mraa,whbruce/mraa,sergev/mraa,Pillar1989/mraa,Propanu/mraa,jontrulson/mraa,malikabhi05/mraa,spitfire88/mraa,w4ilun/mraa,jontrulson/mraa,Hbrinj/mraa,petreeftime/mraa,Hbrinj/mraa,andreivasiliu2211/mraa,stefan-andritoiu/mraa-gpio-chardev,alext-mkrs/mraa,whbruce/mraa,KurtE/mraa,intel-iot-devkit/mraa,jontrulson/mraa,ProfFan/mraa,alext-mkrs/mraa,petreeftime/mraa,stefan-andritoiu/mraa-gpio-chardev,ProfFan/mraa,yongli3/mraa,intel-iot-devkit/mraa,stefan-andritoiu/mraa-gpio-chardev,KurtE/mraa,stefan-andritoiu/mraa,sergev/mraa,w4ilun/mraa,g-vidal/mraa,yongli3/mraa,malikabhi05/mraa