add support for sandia
Summary:
- the factory build uses a different platform name
- new flash procedure
Test Plan:
```
0 ~/local/openbmc/tools/flashy $ ./build.sh && ./build_dev.sh && go test ./...
ok github.com/facebook/openbmc/tools/flashy 1.478s
ok github.com/facebook/openbmc/tools/flashy/checks_and_remediations/common (cached)
ok github.com/facebook/openbmc/tools/flashy/checks_and_remediations/galaxy100 (cached)
ok github.com/facebook/openbmc/tools/flashy/checks_and_remediations/wedge100 (cached)
ok github.com/facebook/openbmc/tools/flashy/checks_and_remediations/yamp (cached)
? github.com/facebook/openbmc/tools/flashy/flash_procedure [no test files]
ok github.com/facebook/openbmc/tools/flashy/install 0.006s
ok github.com/facebook/openbmc/tools/flashy/lib/fileutils (cached)
ok github.com/facebook/openbmc/tools/flashy/lib/flash (cached)
ok github.com/facebook/openbmc/tools/flashy/lib/flash/flashcp (cached)
ok github.com/facebook/openbmc/tools/flashy/lib/flash/flashutils (cached)
ok github.com/facebook/openbmc/tools/flashy/lib/flash/flashutils/devices (cached)
? github.com/facebook/openbmc/tools/flashy/lib/logger [no test files]
ok github.com/facebook/openbmc/tools/flashy/lib/step (cached)
ok github.com/facebook/openbmc/tools/flashy/lib/utils (cached)
ok github.com/facebook/openbmc/tools/flashy/lib/validate (cached)
ok github.com/facebook/openbmc/tools/flashy/lib/validate/image (cached)
ok github.com/facebook/openbmc/tools/flashy/lib/validate/partition (cached)
? github.com/facebook/openbmc/tools/flashy/tests [no test files]
? github.com/facebook/openbmc/tools/flashy/utilities [no test files]
0 ~/local/openbmc/tools/flashy $ echo $?
0
```
Reviewed By: kawmarco
fbshipit-source-id: 6065d1537c512a88040d5f8fcc8d3b863b9fe9f9
