gpio: add mmap enable function to cpp headers
gpio: add mmap enable function to cpp headers

Signed-off-by: Thomas Ingleby <cea8b9d820e871fd22532c955ca84ff867a004a3@intel.com>

Hbrinj/mraa,andreivasiliu2211/mraa,timrtoo/Intel,pctj101/mraa,ncrastanaren/mraa,sundw2014/mraa,nioinnovation/mraa,w4ilun/mraa,yongli3/mraa,yangjae/mraa,timrtoo/Intel,Propanu/mraa,petreeftime/mraa,stefan-andritoiu/mraa,intel-iot-devkit/mraa,yongli3/mraa,noahchense/mraa,arfoll/mraa,intel-iot-devkit/mraa,Jon-ICS/mraa,pctj101/mraa,andreivasiliu2211/mraa,jontrulson/mraa,petreeftime/mraa,sergev/mraa,alex1818/mraa,ncrastanaren/mraa,alex1818/mraa,stefan-andritoiu/mraa,intel-iot-devkit/mraa,alexandru-elisei/mraa,SyrianSpock/mraa,ncrastanaren/mraa,yangjae/mraa,alext-mkrs/mraa,stefan-andritoiu/mraa,petreeftime/mraa,whbruce/mraa,stefan-andritoiu/mraa-gpio-chardev,matt-auld/mraa,sergev/mraa,Jon-ICS/mraa,whbruce/mraa,KurtE/mraa,sergev/mraa,g-vidal/mraa,arunlee77/mraa,Propanu/mraa,STANAPO/mraa,seem-sky/mraa,malikabhi05/mraa,whbruce/mraa,yangjae/mraa,noahchense/mraa,alex1818/mraa,sergev/mraa,timrtoo/Intel,pctj101/mraa,pctj101/mraa,neuroidss/mraa,KurtE/mraa,zBMNForks/mraa,Kiritoalex/mraa,arfoll/mraa,yangjae/mraa,tripzero/mraa,g-vidal/mraa,yongli3/mraa,SyrianSpock/mraa,allela-roy/mraa,nioinnovation/mraa,yongli3/mraa,w4ilun/mraa,STANAPO/mraa,alext-mkrs/mraa,alexandru-elisei/mraa,intel-iot-devkit/mraa,arunlee77/mraa,stefan-andritoiu/mraa-gpio-chardev,malikabhi05/mraa,neuroidss/mraa,andreivasiliu2211/mraa,alext-mkrs/mraa,ProfFan/mraa,intel-iot-devkit/mraa,STANAPO/mraa,Pillar1989/mraa,jontrulson/mraa,neuberfran/mraa,SyrianSpock/mraa,KurtE/mraa,neuberfran/mraa,g-vidal/mraa,seem-sky/mraa,malikabhi05/mraa,allela-roy/mraa,seem-sky/mraa,malikabhi05/mraa,petreeftime/mraa,seem-sky/mraa,jontrulson/mraa,neuberfran/mraa,stefan-andritoiu/mraa-gpio-chardev,damcclos/mraa,sundw2014/mraa,tripzero/mraa,Pillar1989/mraa,Hbrinj/mraa,spitfire88/mraa,neuberfran/mraa,mircea/mraa,sergev/mraa,arunlee77/mraa,spitfire88/mraa,Kiritoalex/mraa,anonymouse64/mraa,Meirtz/mraa,malikabhi05/mraa,anonymouse64/mraa,Propanu/mraa,yoyojacky/mraa,noahchense/mraa,arunlee77/mraa,allela-roy/mraa,KurtE/mraa,KurtE/mraa,Jon-ICS/mraa,smileboywtu/mraa,noahchense/mraa,w4ilun/mraa,neuberfran/mraa,alexandru-elisei/mraa,spitfire88/mraa,timrtoo/Intel,jontrulson/mraa,alexandru-elisei/mraa,seem-sky/mraa,Hbrinj/mraa,ncrastanaren/mraa,zBMNForks/mraa,stefan-andritoiu/mraa,Pillar1989/mraa,arfoll/mraa,g-vidal/mraa,whbruce/mraa,zBMNForks/mraa,damcclos/mraa,Meirtz/mraa,mircea/mraa,sundw2014/mraa,yoyojacky/mraa,stefan-andritoiu/mraa-gpio-chardev,arfoll/mraa,mircea/mraa,spitfire88/mraa,sundw2014/mraa,timrtoo/Intel,matt-auld/mraa,damcclos/mraa,w4ilun/mraa,Hbrinj/mraa,ncrastanaren/mraa,Propanu/mraa,stefan-andritoiu/mraa-gpio-chardev,alext-mkrs/mraa,arfoll/mraa,alexandru-elisei/mraa,matt-auld/mraa,tripzero/mraa,alext-mkrs/mraa,Kiritoalex/mraa,g-vidal/mraa,neuroidss/mraa,pctj101/mraa,Meirtz/mraa,sundw2014/mraa,yongli3/mraa,andreivasiliu2211/mraa,jontrulson/mraa,smileboywtu/mraa,nioinnovation/mraa,ProfFan/mraa,ProfFan/mraa,stefan-andritoiu/mraa,smileboywtu/mraa,ProfFan/mraa,yoyojacky/mraa,noahchense/mraa,anonymouse64/mraa,Propanu/mraa