Convert to SPDX license tags

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

sel4vmmplatsupport: rm map_ut_allocman_reservation

Remove this helper mapping function as it is unused and allocations
should occur through the vka interface rather than the allocman
implementation.

trivial: Style changed files

libsel4vm: Removed page_size field in VM object

Removed the page_size field in the VM object. The page size of
allocations and mappings can be left to the library user to
define. Updated uses of the page_size field to directly define the
page size value instead.

libsel4vm: Moved memory utils into vmmplatsupport

Moved the guest memory utils interface into libsel4vmmplatsupport.
This interface better exists in libsel4vmmplatsupport as its more
relevant to support vmm devices and drivers. This in turn
simplifies libsel4vm's interfaces.