Update load_images.sh to MCP@aarch64

Update load_images.sh to MCP@aarch64

The load_images.sh script still contained old functionality.
The changes are:
- don't use TestVM anymore, MCP does not load that by default like Fuel did
  upload the cirros image instead
- don't upload the kernel separately for aarch64, one part image works now
- add the needed extra-properties accordingly to each image

The script was tested on arm, the test are running now without errors

JIRA: ARMBAND-285

Change-Id: Iee8ce6cde43bebceb2edbb1310ea81c665876aff
Signed-off-by: Cristina Pauna <cristina.pauna@enea.com>
(cherry picked from commit af71c468fe83a5149e0e18cdb233e059302209e3)