Convert to SPDX license tags

Signed-off-by: Gerwin Klein <gerwin.klein@data61.csiro.au>

trivial: Style changed files

libsel4vmmplatsupport: Realloc devices in temp var

Updated the 'add_device' function to realloc the extended device
list into a temp variable in case of a failure.

libsel4vm: Moved/Refactored device datastructure

Moved the arm device management datastructure that existed in the
arm source out to libsel4vmmplatsupport. Internally we don't need
to use the device datastructure since internal drivers use the
memory interface for registering fault callbacks. The device
datastructure can rather be used as a management utility for
VMM's.