[SDK tools] Support non-ASCII paths in 'mksdcard'

Use platform-specific code to support extended character
sets on Windows, Mac and Linux.

Merged from b2d5e1171803b3229c64f8dfd2c576e8a80c5901

Change-Id: I2065bbf4eb6aa7f860ad0779bf81f9fda7a54e57
Fixes: 113514423
Test: Manually verified with path 'Юзер' on Windows, Mac, Linux
1 file changed