Set cuda device to second device

lib/libstereo/middlebury/main.cpp

lib/libstereo/src/algorithms/brefcensussgm.cu

lib/libstereo/src/algorithms/censussgm.cu

lib/libstereo/src/algorithms/hcensussgm.cu

lib/libstereo/src/algorithms/meancensussgm.cu

lib/libstereo/src/algorithms/stablesgm.cu

lib/libstereo/src/algorithms/tcensussgm.cu