cmake: VL_DISABLE_SSE2 when building on other architectures
cmake: VL_DISABLE_SSE2 when building on other architectures

SSE2 is an x86 specific instruction set, so disable it when building
on other architectures.

Signed-off-by: Tyler Baker <b3cc311ecf91e7c5c184946246e38d36003af74d@linaro.org>

sunbingfengPI/OpenSFM_Test,mapillary/OpenSfM,oscarlorentzon/OpenSfM,BrookRoberts/OpenSfM,mapillary/OpenSfM,BrookRoberts/OpenSfM,sunbingfengPI/OpenSFM_Test,sunbingfengPI/OpenSFM_Test,sunbingfengPI/OpenSFM_Test,mapillary/OpenSfM,sunbingfengPI/OpenSFM_Test,BrookRoberts/OpenSfM,oscarlorentzon/OpenSfM,oscarlorentzon/OpenSfM,BrookRoberts/OpenSfM,mapillary/OpenSfM,BrookRoberts/OpenSfM,oscarlorentzon/OpenSfM,mapillary/OpenSfM,oscarlorentzon/OpenSfM