uart.hpp: Use std::string constructor which lets use set a size parameter
uart.hpp: Use std::string constructor which lets use set a size parameter

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

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